Unfortunately, we don't really know much about this Restaurant City offering. Inside Social Games reports that the game will be an entirely new experience, apparently independent of our Facebook restaurants, without any actual connection. Anything beyond that is still a bit unknown, other than the fact that Facebook Connect will be integrated somehow (if we're guessing, it would be through wall posts alerting your friends to your progress).
We've reached out to both EA and Playfish for comment, and will update this space as we know more.
What do you think of the idea of playing a Restaurant City on your iPhone or iPad? What do you think the game will entail, if it's not directly connected to our Facebook restaurants? Speculate with us in the comments!