Actions points are no longer increased by stats and the only way to have more is to either wait your turn to keep the remaining ap (you are still capped at 6 ap max if you do so) or having skills or traits giving you ap.
Adrenaline is a scoundrel skill giving you 2 ap now but next turn you will only gain 3 ap instead of the regular 4.
Flash Sacrifice the racial skill from the elves gives you one ap.
Executioner the trait (you need 1 wafare to pick it), gives you 2 ap when you finish off someone.
Haste (available in Pyro and Huntsman spec) allows you to gain 5 ap per turn instead of 4.
I think these are the main skill in EA to have more ap.
Maybe in the game some items will give more ap or whatnot.
Now be aware the skills are being balanced and what you can do now won't necessarily be as good in release.
For instance we know Adrenaline will be nerfed a little so that the next turn you only have 2 ap instead of the current 3.
And Executioner will only proc once a turn (in the EA you gain 2 ap as long as you kill one peron per attack indefinitely).
