I made the jump to FF last year, sold my 10-22 and bought the 17-40 as my UWA. I was a bit apprehensive at first as I loved my 10-22 but I have to say the 17-40 is sharper and has better contrast. And it's built like to last. Sure, corners are a bit soft wide open at 17mm but for landscapes you wouldn't use it at f/4. The 35 - 40mm range is really nice IMO which makes for a pretty decent walkaround on either crop or FF. Depends on what you shoot of course.
I also have the 17-55 which is a very useful lens, though I don't entirely agree with the price! Buy it second hand then sell it once you move to FF if you go that route. The IS on the lens is actually pretty good, I can get about 3 stops from it. Very useful for night landscape and urban shots where run and gun style is pref over tripods. Wide open performance is surprisingly good too, quite sharp. A great lens for portraits and occasional landscapes. It is built well but it still makes me nervous when it dangling at my side on a r-strap. Lens creeps like a mofo.
If you are really into the wide angle perspective 24mm won't cut it on FF. To be honest I think 17mm is not wide enough for my tastes but it gets the job done.