Last week the release candidate for Windows 7 was made available to the general public. Being the leading edge sort of a person I am, I spent the day trying to get it downloaded and installed. If you upgrade from Vista, expect the installation to be very long. AND, I found that strange things happened with the upgrade.
I then did something drastic - I did a new install of 7 and erased Vista! Windows 7 seems to run a little better and the install was much quicker. BTW, unless you hack the download file a little bit, what you will install is the Ultimate Edition. Not sure what that really gives you yet (I need to read more), but it will last until June of 2010. At which time you must buy 7 or go back to a previous version.
The UI is slightly different than Vista - maybe better?!?! It may load a little faster and I think hibernation is faster, too.
More later.