For those who haven't gotten their hands on an Windows XPSP2 CD, new .NET Framework SP's are now available, for versions 1.0 and 1.1 (the first version of 2.0, or "Whidbey" is still yet to be released).

Here are the links to Microsoft's download center, the related "Knowledge Base" links may not become active on the web for a couple hours.  When they become active, you'll be able to see a list of fixes included in these service packs.  Rest assured, these patches are a culmination of a ton of work (by the .NET Framework team, and my team).  In a couple of days, they should also become available via Windows Update.

.NET Framework Version 1.1
Service Pack 1 for All OS's other than Windows Server 2003
Service Pack 1 for Windows Server 2003

.NET Framework Version 1.0
Service Pack 3 for All OS's other than XP for Tablet PC / Media Center

Notice there are two links for the 1.1 version: it's because the .NET Framework is installed via Windows Installer technology on most operating systems, but is incorporated as an OS component for Windows Server 2003.

Likewise, 1.0 .NET Framework was incorporated as part of the XP version for Tablet PC / Media Center.  So those users will actually get SP3 for the 1.0 .NET Framework by simply installing XPSP2.

If you're running Windows Server 2003, you should reboot after installing the 1.1 Framework SP in case some files (e.g. DLL's in the CLR and base class libraries) were in use during installation.  The patch on Windows Update will always ask for reboot for the 1.1 SP1 patch.
[Microsoft WebBlogs]