Soon Windows Vista SP1 will be available for download. Or actually, it might even decide to automatically update itself, even though you specifically told it not to! However, not all of us want this to happen without our knowledge (or want to wait until some unexpected behaviors has been discovered), so Microsoft has release a service pack blocker. This blocker will also work for Windows XP and Windows Server 2003. The blocker only work for a set period of time. Mary Jo Foley has more details in her blog.