The main "bugger-factor" of the ARM7TDMI over the XScale and StrongARMs is its 16-bit Thumb instruction set (the T in the TDMI). Some of the custom graphics stuff in the GBA should be relatively easy to emulate though. Even with "only" a 200MHz StrongARM you're looking at a 12.5 times speed advantage (and a much greater bus/memory speed). If you can get the PocketPC to natively execute the code that it can, then you should be alright (or "dynarec"ing the Thumb to ARM should be relatively straightforward).
How're you guys planning on handling the Thumb stuff (Rob, Jadam)?
