Aniplex USA has started a poll on their Facebook page asking people which of their titles they'd like to see on Toonami.
So far, the most voted shows are Madoka Magica, Fate/Zero, and Gurren Lagann.
Fate/Zero looks like it would be a good show. And I still think that Gurren Lagann is one of the shows that HAS to be on Toonami as some point.
Madoka Magica though...I say no. A show filled with cutesy moe girls isn't going to keep [adult swim]'s casual audience around.