SQL Server 2008 CTP6 hit the streets today. You can get it here:
It's getting pretty close to feature complete now. Microsoft is keen to have it tested like no other version before. To assist with this, they've introduced a bug bash competition with a bunch of XBox's and other interesting prizes if you help find issues with the CTP. Details are here:
http://connect.microsoft.com/SQLServer/content/content.aspx?ContentID=7734
It's time to go bug-hunting !