According to S. "Soma" Somasegar (corporate vice president of the Developer Division at Microsoft), WinFX is dead - long live .NET Framework 3.0!
In his Blog he writes that: "The .NET Framework has always been at the core of WinFX, but the WinFX brand didn’t convey this.." and so, "With this in mind we have decided to rename WinFX to the .NET Framework 3.0."
.NET 3.0 will come as a standard part of the forthcoming Windows Vista and will also be available for use with XP.