I've received the following type of question a few times and would like to give the answer with some background:
Q. Where is the .NET Framework 3.0 SP1 & 2.0 SP1 for Vista RTM?
A. .NET Framework 3.0 & 2.0 released with Vista as OS Windows Components, which means that they are serviced as any other windows Component. Therefore, the .NET Framework 3.0 & 2.0 Service packages will be officially released as part of the Vista Service packages. When Vista SPX is shipped then .NET Framework 2.0 & 3.0 might also include updates in that service package.
In this case the .NET Framework 3.0 & 2.0 have a service package that will be shipped with Vista SP1. Vista SP1 RC is available now (http://technet.microsoft.com/en-us/windowsvista/bb738089.aspx)
NOTE: The same logic stated for Vista and .NET Framework will also be true for Windows2008 & .NET Framework 2.0 & 3.0, only Windows Server2008 will release with .NET Framework 2.0 SP1 & 3.0 SP1 in the OS.