I hope they will stick with the average for player HP. Otherwise they will skewer balance again in favor of d10 classes and especially barbarians..
Not even that, you get a few dodgy dice-rolls at levelup and your front line fighter's only got 14 health. At which point they're just dead weight.
Yeah random HP has never been a good idea. It's just a way to randomly ruin a character or make them mysteriously tougher than others. "Why is that 16 Con Fighter squishier than the Wizard" is a tough question to answer.
I also hope they're going to buff 1st level hp in 6e. One hit kills are just dumb when it's not even a critical hit. Something like Con score + HD avg would be appropriate imo to buff the starting HP to around 14-23.