If anything, I seriously doubt we'll see any crossover between CN and AS anymore. It seems like CN is intentionally skewing much younger now with it's programing-more to the 8-10 year old audience. They've eliminated all classsic cartoons, toonami is a non-entity, and the shows they do air hardly have the same cross-over appeal. Additionally, both networks have taken steps now to really show they are independent from one another. CN has started airing the "Goodnight see you tomorrow" commercial everynight at 10:59. Officially CN only programs from 6 am to 10 pm, while adult swim programs the rest.
Considering Nielsen now counts the two networks as seperate, the completely different audience focus, and the lack of shows on either network that could run-I don't think we'll see any crossover.
If I had to name a few that were possibilities, "the popeye show" and "the bob clampett show" are probably the only shows that have aired on both. Inuyasha and the tamer dub of shin chan probably could (with a little censorship).