On my Windows XP computer, Microsoft automatic updates suggested me to do a brand new installation of .NET Framework 3.5. I checked and the last version of .NET I have on this computer is 2.0. So Microsoft is trying to make me install a brand new version of their library hiding it as an update. It certainly containes "many new features built incrementally upon .NET Framework 2.0" , as the description suggest...

Oh, by the way, in case I had automatic updates (I hear them saying, "you need automatic updates for real security") I wouldn't have even noticed... I think this hidden installation goes very close to the border of Microsoft antitrust regulations. It clearly puts Microsoft at a big advantage over Java (and even Flash) because it can push its library updates, including Silverlight support, along with the operating system. More or less like they used to do with the browser. Needless to say, I didn't appreciate and cancelled the huge download.