Microsoft announced on Friday that they're going through a bit of renaming. The post title says it all, but let me give a bit of background (actually, this post has a bit more info to add).
WinFX, for those that don't know, is basically the successor to Win32. It's a .NET API framework for some of the new techologies coming out of Microsoft. The three big names in it for this release are Avalon (aka Windows Presentation Foundation), Indigo (aka Windows Communication Foundation) and InfoCard. However, there are several other APIs that have been added to provide more Win32 abilities from within .NET.
However, there seemed to be some confusion over the difference between the .NET Framework, which has a bunch of .NET APIs, and WinFX, which has a bunch of .NET APIs. So it was decided to drop the WinFX name and go with just the .NET framework. Thus when Vista ships, what is available is .NET 3.0 - not WinFX. But this is pretty much a naming change - what is going to be available is the same as before.
An interesting note is that Vista is going to come pre-installed with .NET 1.0, 1.1, 2.0 and 3.0 - so you're ready to .NET the night away!