There's enough already been written about Tomb Raider elsewhere, and I don't want to get into the whole rape scene debate here. But I have a new preview of the game in this month's issue of PCPowerPlay, and I'd say it's worth a read.
My contention is simply this - we don't have enough context to determine if this scene is gratuitous. I reject the notion that by its existence this scene ruins the game or is somehow "immature". That may very well be the case - but we need to wait until the game is out for us to fully tell if that's true.