After a little more than a year in the wild, it’s high time for Windows Vista to receive the service pack it deserves. While Service Pack 1 won’t change the way Windows Vista looks or feels, for the most part, it will improve many things about the way it runs, based on both Microsoft ‘s internal testing and the feedback of tens of thousands of users.
SP1 has been both heavily anticipated and badly needed. While the gold release of Vista was for the most part solid enough to use as a production system, there were still many frustrating rough edges.
In the light of these problems, one of the most commonly repeated canards about using Vista was, "I’ll just wait until SP1 comes out." Well, SP1 is now almost out. A release candidate, which is the version we tested, was made available towards the end of last year. More recently, Microsoft officially released SP1 to manufacturing in February to TechNet and MSDN customers. The actual, wide public release to users at large is expected sometime in March. 

Full story: InformationWeek