Just like to publicly thank Brad for talking about this in the quicklook. I honestly just was watching it for his funny reactions to shit going crazy and sorta half paying attention until I was like WTF?!?!
If anyone doesn't know you can check a box named elective mode and it totally can change what abilities you choose. Just do a search on diablo 3 and that term, I'm sure people have mentioned it elsewhere. Basically you can are no longer limited to 1 skill per "group", but still the same amount of overall usable skills.
For those who are going to be like... DUDE WTF YOU ARE A NEWB!! Ok thanks... but seriously no tooltip or anything popped up telling me about that, how would you know if you didn't read online or someone told you (both of which didn't happen till Brad).
BTW I was freaking level 27 when I found out about this, and my skill bar totally changed!