It's a bit awkward having to open a separate tab to get to the skill tree - wouldn't it be nice to have another panel in the accordion on the right for your skills, abilities and achievements?
While i'm sure this is already being planned, i just wanted to pipe in that I like having the skill page being at least viewable outside of the game (even if not editable in the future), just so I can see the skills that other people have, and make or get recommendations on how to spend skill points.
like yeoz, I find it more useful out of game tab - though no objections to an in game version.
although at some point the game interface is going to get so crammed with stuff that it will become intimidating. the game interface already is a bit intimidating to me now. it is tempting to want everything crammed in there but at some point something has to give.