Too much importance on ability scores.
I certainly like using all 6 ability scores as saves, and do so in my games already, but hate the importance of ability scores for skills. Ability scores for me are just a measure of character potential and not a fixed gage of character power. 18 Str, you are potentially a strong person, but if you don't train, you're going to suck at swimming. 16 Int, you are potentially a smart person, but if you don't read those books and study hard, you're gonna suck at knowing things. While I am a firm believer that no + should ever exceed the dice rolled (so no d20+23), I think they can do a better system than relying on ability scores for everything, especially skills. Training should matter more than raw potential. There also should be a greater differential between numbers than +2 to show skill in an area. If you're a 1 and I'm a 10 that's a difference. If you're a 6 and I'm a 4, not enough different to bother with.
I also don't want to bother negotiating with players every time a skill is used. "but my +2 in orc military history means I get a +2 on goblin history because they fought several wars against each other." "But my +2 make-up artist allows me to paint my face in such a way that allows me to use it with a stealth check." Too much of that is really going to get annoying. Too much history has past since the DM rules all system. While I still use it to a greater or lesser extent, as do we all, I don't want it to be the primary method for resolving every little +2 in the game. I'm hoping this is a exaggeration and that the play-test product will have more meat on its bones.
As always, I reserve the right to change my mind, as do we all!