I just noticed a blog post made yesterday by S. Somasegar (the vice president in charge of developer tools at Microsoft). In it, he announced a naming change for the WinFX - it will now be known as the Microsoft .NET Framework 3.0. I encourage you to look at his blog post to see more details about the change and why it was made.
Please note that this is just a naming change, the features that are a part of the .NET Framework 3.0 are the same and so are the ship vehicles and schedule. The .NET Framework 3.0 will be a part of the OS on Windows Vista, and will be availabe as a redistributable package on Windows XP and Windows Server 2003.
It will be a little odd because on downlevel platforms, when you install the .NET Framework 3.0, it will actually install the .NET Framework 2.0 as a prerequisite, so you will see both the 2.0 and 3.0 versions in Add/Remove Programs after installing it. Also, uninstalling the .NET Framework 3.0 will leave behind the 2.0 version because other applications (such as Visual Studio 2005 and SQL Server 2005) might be relying on that product being installed to work correctly.