Update Vista Sp Not Presented

When I checked Windows Update today, 2nd Tuesday of March, I found only one new Vista update (.5 MB) which actually has a date of Feb 12th. I thought SP1 would be available today for the "first wave (English)" version. I'm using Ultimate installed by the manufacturer and have kept it up to date (except for hiding unneeded updates like the foreign language stuff and the test for counterfeit versions). Microsoft has a web page listing the SP1 roll-up files which also says that the service pack will contain additional files not in the list: "This document contains a list of these updates with links to their descriptive web pages on. There are other updates in Windows Vista SP1 which have not be released as updates and therefore are not presented in this list."