See now I have pre-ordered a copy of 7 pro for cheap, but the more I think about it the more I'm thinking: "Is 7 really that much better than vista" and "does 7 do things which I do that vista doesn't do very well".
In all honesty the answer to both questions is no. Vista 64 for me has been rock solid since sp1, since sp2 was released I've found it a breeze and just as fast as 7 when I tried the rtm.
If you are buying anew then you may as well get 7 as it is released very soon, if you are upgrading from vista I wouldn't bother to be honest I beleive the improvements are negligible.
I'm more than likely going to cell my retail copy of 7 pro as soon as it arrives at my door, i'll probably make a tidy profit.