AI-Net is proprietary, and it's unlikely to be standard RS232 so no, the current hardware couldn't talk to it. However, it's very likely that a converter could be made given enough coffee & a logic analyser - but it'd be underselling the empeg a bit hiding it away ;)

It can't play MPEG movies as there's no video out and the display isn't really up to playing movies :) (CPU power might be an issue too - you could probably get MPEG1 but that's it).

Hugo