I'm still sitting on my 20D and waiting
I've just been putting money into lenses because honestly, that is where you really see the difference in your photos. Plus, if I do get a nice FF, I will need some good glass for it.
Whether it is a 3D or 5D, the next cheap FF is what I will be watching for very intently.
One of the big problems with the crop cameras is that your lens choice for wide angle (less than 16mm so that after crop it is under 24mm) are very limited and there are no high quality (L) lenses available in this segment.
Yup, that's true. One of the bummers for crop cameras. I personally don't shoot very much (at all) wide angle stuff. My widest lens is a 24mm which converts to a 38mm...not very wide. I mostly shoot portraits so I get by. I figure when I get my FF finally, that 24mm will look
real wide

I might also consider the 16-50 that is rumored (if they actually make it) as that would give me a lot wider view than I am currently used to, and still work on a FF later. Of course, that is just a rumor, and I do need to keep saving since I don't currently have enough for a FF yet.
Honestly, even more than the wide angles, I am looking forward to being able to use my 70-200 2.8 in more confined spaces. I love that lens, but sometimes it is just a bit too long on my 20D.