Very interesting, but lol.  It's like asking the person who invented sex what other things he's moved on to.

Seriously, I can't imagine anything Satoshi can do that would top bitcoin.  Even if he has a million good ideas from now until doomsday, he could always rest on his laurels knowing he invented bitcoin.  It's really a shame that there's no Nobel prize for computer science, although the creation of bitcoin might qualify for the economics prize...tho awarding it might present somewhat of a problem assuming Satoshi's identity remains unknown.