In two minds about W7, and plan to try the RC this weekend. But currently swaying to skip this version due to the reasons below.
Main issue I have is my limited time of ownership of Vista. Especially as I could have probably of continued with XP and lived with not seeing all my RAM. Only got Vista for 4GB RAM support.
I bought Vista post SP1, think May 2008. And as I went retail version and the additional 64-bit media order it came to around £140. So I don't fancy paying more for an optimised version, just because Microsoft's strategy didn't anticipate netbook and low spec PC popularity.
As hardware advances it should allow Vista to run smoother. And as I can't really install Vista on my older hardware, it would become an expensive shelf ornament if I switched to W7.
On the other hand I know next year, once the special discounted pre-order price is a forgotten memory, I'll miss some feature, or improved performance, that is W7 promises, e.g. maybe TRIM command for SSD's.