With the whole Vista and Office '07 thing, its a bit of a case of Cursed if you do, Cursed if you don't.
For those who are happy to stick with XP and previous Office versions, we know it all works, and we know how to use it - But eventually, these people will be left behind.
On the other hand, those of us who upgrade are presented with software that doesn't work exactly as expected, and takes a bit of getting used to. I for one find Office '07 a bit of a learning curve, especially that ribbon thing up the top. I spend a little bit longer looking for something than I do using the '03 version - but once I find it in the new version, i'm going "Yeah, that makes sense... it's much better to put that feature there" and now i'm getting the hang of it.
And for those people who say *** microsfoft... *** no testing... grumble grumble gripe moan I say this:
It's basically impossible for a Software Developer to test their product with every single combination of hardware and software on the market. If they did so, we'd be looking at decades between new software releases, at which point there would be new hardware available to test and so on and so forth. It would be a never-ending cycle of program testing and redevelopment, and nothing would ever get done.
So! I say get out there, try the new stuff, see if you like it.
If you don't, don't use it - but you'll have to upgrade sometime.