Yeah, once the whole 'marraige trend' fades... everyone will probably be splitting for some reason or another - probably to get their names back in the papers..
i don't know if it's true, but according to ET, it's just a hoax on the couple's part. who knows? as long as they're happy & having fun, it's all good.
I heard from my friend who used to work on some small shoots in Hollywood that a lot of celebrities do this before a new movie release or to get more publicity and then they get divorced after the goal has been accomplished.