Mike Nash just announced on the Windows Vista Team Blog some specific availability dates for Windows Vista Service Pack 1 (SP1). 

As you probably know,

Windows Vista SP1 RTM'd the same day as Windows Server 2008 (Feb 4, 2008), but while Windows Server 2008 was made available to TechNet and MSDN subscribers, SP1 was not.  There were a bunch of reasons why, Mike’s blog posts will explain.

From feedback of the IT Pro community, the availability dates for the technical audiences were actually moved up from when they were originally scheduled for.

So... when can I get it?

If you were a Vista SP1 Beta tester for us, you can download it right now.

Volume Licensing customers will have the English version available on Friday of this week (February 15, 2008).  Other languages will be available soon after.

And those of you with an MSDN or TechNet Subscription will be able to get it later this month.  (Another really good reason why you should have a TechNet Subscription .)

You can read Mike Nash's posting about the announcement here.