Visual Studio.NET 2003 - SP1
If you thought that after the release of Visual Studio.NET 2005 with all its fancy editions, MS would stop investing any time in VS.NET 2003, you thought wrong!
A service pack (SP1) is scheduled for RTM on June 1st, 2006. If you would like to attend the beta-program, you can apply here, but be quick: the beta is scheduled for March 24th.