This game is built around being able to adapt your character quickly to different situations, however the current system is terribly clunky and slow when trying to dig through menus to change skills around.
There are addons out there like Wykkyd's Outfitter, but they don't work reliably. Things get backed up when your group goes into combat (Dolmens) and then suddenly you hear it trying to change your abilities 4000 times and you get disconnected from the server.
A simple system where you could hotkey sets of abilities; is it really so much to ask?