I just built a new system with Vista 64. Should i download the new Windows 7 ? I have it on my laptop and really like it. I have heard that the RC build 7100 trial comes to end June 1st, if so what happens then ?
Run the RC until it runs out, then buy the full version of Windows 7
When the RC comes near its expiry it will start with bi-hourly shutdowns (i.e. every two hours it will be unusable for 2 hours). Eventually it will be completely unusable at which point you will need to install a full OS
The beta release expires july 1.2009.
The release candidate will still run until well after the official release is out.
The official release will require a clean new install, not a repair or upgrade install. If you are ok with that, and it's trial status, then get the release candidate.