I hope fc3 moving away from Dunia and towards another cry engine might allow the maps to become available to players on any of the three systems. Cross platform pollination could be difficult but if ubisoft exported the recommended and adds them to all the skus it could be an absolutely amazing multiplayer network.
I wouldn't wana see any far cry 2 maps on there but it would be cool if you could play both ps3 and xbox maps linked up in one network. It's not likely probably way too complicated but it would be pretty cool that way we don't miss out on any great maps on other consoles. i did leave out pc just because they tend to be higher performance of course.