There's a new article on MSDN. It's a good read when you're trying to decide between static vs. dynamic linking but here's what I think is the most important part for people to keep in mind:
For Windows Mobile platforms, MFC 3.0 is in read-only memory (ROM) for backward compatibility, but MFC8.0 is not ensured to be on the device. Therefore, application developers need to ensure that they package the MFC 8.0 runtime with their applications.
The Migration FAQ is actually a bit more aggressive on this topic and says:
The runtimes for prior versions of ATL and MFC [...] will be removed in future versions of Windows Mobile. Therefore, developers should either migrate to MFC 8.0, ATL 8.0, or redistribute the older runtimes with their applications.