I don't think the wealth of options previously mentioned for "active combat" systems would work well if flight is controlled at the same time – that would be too many keys to press simultaneously. However, that also depends on how flying opponents fight. One can think of a rather stationary battle where the opponents more or less hover, move only slightly back and forth (as well as up and down) or circle each other while almost continually attacking each other – comparable to the ground combat of opponents on foot. There could also be a battle comparable to the fight of knights with lances on horseback: They charge at each other (or one of them at the other one), only trying to hit when they are close to each other ... and maybe using ranged weapons the rest of the time.
well yeah something comparable to knights with lances might work, but air to air it would be quite a distance to fall. So you can't ever lose and live to tell.
(but I guess that wouldn't be a problem)

I can also imagine leaving the flying to the computer during a fight, especially if the player character is just the rider. You could give some general rules on what your steed should do, much like you'd set actions for your companions on the ground. A click on the ground or on an enemy would be enough to override those general rules and bring you there (without changing height) or make your steed follow the selected enemy. It's like shouting commands to your steed: It follows them, but they aren't precise enough to make you feel like you'd fly on your own.
Fully controlling how your steed moves would be an option, however. In most RPGs you have full control of the horse you ride, so if it's possible to ride a flying creature, I see no reason why one shouldn't be able to control it as if it was one's own character – as long as this can be done in a simple way.
So wich one do you prefer ? Unless we aren't the flying creature ourselves we really shouldn't be able to control it as well.
Or maybe like in Zelda OoT (forgot what it was like in the other zelda games)
we can control the horse (flying creature) easily when riding or in this case flying(wasd+mouse, also for height).
But you can't really see what you are doing when drawing your bow and riding the horse
(you can look left and right, while as you were the flying creature looking left and right would be alot harder).
And you can still control the horse as you are using the bow, but for example when there's a wall in front of you.
Your creature shouldn't be dumb enough to just keep flying towards the wall to hit it with its head.
So I would want to be able to give the creature a mind of its own.
Targetting might work when going after one single enemy just telling your creature to follow that target but still use manual aim for bows, fire balls, etc...

Another thing that crossed my mind: If we get to play a dragon, weight might play an important part in speed considerations. A dragon should quickly gain momentum when diving, while going up might be a way to quickly lose speed. Of course, that's based on the assumption that dragon flight also relies on the dragon wings and isn't purely magical.
Personally I would want the flying rely on wings (dragon or not) I'm not really in favor of the superman flying style.
So I would want the speed to increase when diving and to lose speed when going up.

Melee combat against many enemies at the same time, by the way, should be much more dangerous than if you fight them one at a time – and one should also gain more experience from it. The picture of someone cutting through a host of enemies while hardly getting hit is quite heroic, but not very believable. If you assume that you don't get hit because you deflect your enemies' blows with your own weapon, you should only be able to defend against a limited number of foes at a time, probably based on your fighting prowess. A typical mage might only be able to use his staff against one enemy's attacks, a skilled fighter would perhaps be able to deflect the weapons of three enemies – unless magically hasted. All other enemies in close combat range should get a considerable bonus on their attacks. Of course, a hit wouldn't necessarily cause damage if your opponents can't penetrate your diamond armour, but they might still be able to send you to the ground, making it easier again to hit you or to use some nasty special attack on you.
Thats only assuming the other enemys would stay off your back when attacking a group.
One way could be to lure them one by one but they really shouldn't be this dumb.
(There could be a specific dumb kind of creatures that would let this happen, but not all creatures should be this dumb)
But as I mentioned, in gothic 3 attacking different enemys sometimes had to be done because different enemys were attacking you.
You wouldn't be able to fight them one by one because you would be dead in no time. At least it was this way for me. So more a defensive counterattack style of fighting would be required.
Unless you could use very high speed to your advantage and fly through them (in the same way as the knights with their lance) and just hit the enemys with your lance/spear or whatever. Maybe you would pass them so that they could only attack your left side and thus making defending yourself alot easier.


Something I'd also really like to see in combat is intelligent foes who know how to use the available tactical options, however they may look like, to their advantage. In my eyes, it's better to have a smaller arsenal of skills and spells which the AI can handle than a larger range of abilities most of which are never used by any computer-controlled creature or character – or if so, only in a random or stupid manner.
Or how about the way guild wars does this ? there are plenty of skills but you can only take some (8) with you. The same goes for your enemys (weaker creatures usually have less).

If the player character becomes famous, intelligent enemies might develop countermeasures to tactics he/she is known to use often. They might focus on his/her vulnerabilities if they are able to discover any; differing enemy behaviour would also increase the replayability. They should take cover when being attacked from the sky without having ranged weapons. And many should try to flee if they realize they don't stand a chance against the player character. Most living beings aren't very fond of the prospect to die at the hands of someone who has just easily killed several of their comrades. Simple undead would be a notable exception; orcs and some human fighters might be if they believe that defeat equals dishonour, but death in battle is honourable. And since we just touched it: The various races and factions of the game should be deeply embedded in a rich background of cultural traditions and philosophies.
I wouldn't want my enemys to live to tell about my fighting style.
But maybe as I am fighting the more intelligent creatures, they would learn from my attacks and won't make the same mistake twice.
About the fleeing that depends on the situation, because I can imagine that dieing from my hands would be better for them than dieing from their bosses hand.
(Has even been done by humans so why not in a RPG world). But once their boss is dead and they know they don't stand a chance, they might run.
But I agree that[color:"orange"] The various races and factions of the game should be deeply embedded in a rich background of cultural traditions and philosophies. [/color]
So they shouldn't all stay because they feared their boss (or stay for honour).

There is no spoon !