According to an article published in the Microsoft's russian virtualization team blog, the Windows 7 SP1 final build is this one: 7601.17514.101119-1850 and will be made available to OEMs these days. Recently we got the update KB976902 that it seems is a prerequisite necessary to install and remove any service packs to all versions of Windows 7 and Windows Server 2008 R2. Another indication that we should expect SP1 to be available soon is that Microsoft made available in November a Service Pack Blocker Tool for download. This usually happens around two months before the official release.
Clearly this was a last minute update to the original post. So guys these are the news on SP1, I think we'll have to wait a little more for the Dynamic Memory feature on Hyper-V.