I made a quick search using IIfx and 6502, and DejaNews (crippled as it is)
returned the following from Linux patches
<http://x68.deja.com/getdoc.xp?AN=703511553.12&CONTEXT=980538148.663027739&hitnu
m=0>
It talks briefly about the issues around the 6502 IOP, whats been done, ie
compatibility mode, and some areas that need looking into.