Source: http://www.microsoft.com/presspass/press/2008/feb08/02-04VistaSP1MA.mspx
… Windows Vista Service Pack 1 (SP1) was released to manufacturing today and will start being available to customers in March, starting with Microsoft Volume Licensing customers.
Windows Server 2008 was also released to manufacturing today and will be available for purchase to new customers on March 1.
flaphead.com 