I have read a few articles about Zynga Casino (home of their Texas
Hold'em and now Bingo) and their intentions seem to be to leverage their brand and move to a real money game environment. They are actively searching out gaming partners from the gambling world
If regulation comes to the US, I expect Zynga to spin off their Casino from Facebook to a real money platform and keep all the $$ instead of sharing/depending on Facebook. How many fishes would follow? I imagine, initially quite a few. But for most of these Zynga players, money has no interest for them... they are into the virtual eye candy.
For all the social gaming platform developers, figuring how to make more $$ off their players is a real challenge. Yep, there is a lot of money in the virtual stuff, but there is a lot more money to be had, if they can figure out how to turn their player base into real money players