They aren't making it clear if it's the 32 or 64 bit version you are buying but you can preorder as of today and there's a discount on the upgrade versions until July 11th or when supplies run out.  Also if you want the download+ship option from Microsoft's site you DO NOT get the pretty packaging.  Just the 7 DVD in a cheap paper sleeve... assholes.

http://en.wikipedia.org/wiki/Windows_7_editions#Comparison_chart

http://store.microsoft.com/microsoft/Windows-Windows-7/category/102

http://www.amazon.com/Microsoft-FQC-00129-Windows-7-Professional/dp/B002DHLVII/ref=cm_cd_pdp?_encoding=UTF8&amp;cdPage=1&amp;newContentID=Tx21XDXEDTRB43Y

Windows 7 beta build 7000 will start rebooting every 2 hours begiining 7.1.2009 and on 8.1.2009 build 7000's license expires and becomes not-genuine.

Windows 7 RC build 7100 is good until 3.1.2010 for the 2 hour restarts and 6.1.2010 for the expiration.

I'm not happy with the pricing.  Considering the economy and the PR hit Microsoft has taken as a result of Vista I think they need to be more aggressive on the pricing.  If they continue to follow Sony's PS3 pricing lead 7 won't do as well as it could.  There are also a few little things in 7 that I consider a DOWNGRADE from XP  - not remembering folder views as well as XP did, not remembering explorer window locations, not able to reopen explorer windows automatically that were open when you shut down... just off the top of my head.  I don't know about Vista and will never install Vista as my main OS but 7 is tolerable and very usable with really good compatibility for older software from what I've seen with the RC.