RC0 means Release Candidate 0. SQL 2012 release date has no been announced yet, but there will be a VLE on the 7th of March>http://www.sqlserverlaunch.com. When SQL 2012 RTM'd then Express edtion will be released
I hope it helps.
There are 10 type of people. Those who understand binary and those who do not.
Proposed As Answer byHorizon_NetSaturday, February 18, 2012 10:33 AM
Marked As Answer by沈世鈞Monday, February 20, 2012 2:01 AM
Microsoft is conducting an online survey to understand your opinion of the Msdn Web site. If you choose to participate, the online survey will be presented to you when you leave the Msdn Web site.