How do I help my friend through her inevitable breakup?

My roommate and her boyfriend are splitting up as he is moving out of the country for a couple years and will be hard to get a hold of. They don't want to do the long distance thing. They've talked about this and agreed that this was best and everything, but that being said, my roommate is still distraught just at the prospect this oncoming problem that will be there in a couple days when he leaves... and I know it will only get worse once he actually does. She really likes him, and I know it will be difficult for her to move on.

How do I help her feel better and get her though this? I really want to be a good friend, and I know she's counting on me to be there to help, but I'm not sure what I need to do, exactly... I try to play the "romantic comedy funny single sidekick girl" but I can only do so much.

Thanks!