Microsoft announced yesterday that it will be releasing Windows 7 Beta 1 on DVD on their US tour next year. They have also announced that they are hoping to have Windows Vista Service Pack 2 finished and shipped by July next year.
They have now finished a test version of Windows Vista SP2 beta and this is publically available today. Information is at http://windowsteamblog.com/blogs/windowsvista/archive/2008/10/24/windows-vista-service-pack-2-beta.aspx and can be downloaded through a customer preview program (CPP) along with the Windows Server 2008 SP2 beta at http://technet.microsoft.com/en-gb/windows/dd262148.aspx. You must currently be a subscriber to either Technet or MSDN to download however a public version will be available in a few days.
I will take a look at Vista SP2 beta soon and report back.