The .NET Compact Framework 2.0 SP2 has been released for mobile devices as a download on MSDN - The March 2007 Windows CE update also includes the .NET Compact Framework 2.0 SP2 bits for the Platform Builder Catalog.
Here's a link to the downloads.
Windows CE 4.2
Windows CE 5.0
Windows CE 6.0
Update name: Windows Embedded CE 6.0 Monthly Update (March 2007)