Actually, would it be a fair statement to say that an Iyonix with Aemulor Pro is actually more backwards compatible than a StrongARM RiscPC was? I'm thinking mainly in terms of games, where self-modifying copy-protect code would stop many old games dead in their tracks, but I'm sure there are some more productive examples as well.
Now all we need is a version of Aemulor that lets Select run on the Iyonix! (I'm joking! Oi! Gerroff! Ouch!)