What the hell is this whole Turkey genocide bill about?

I really try to follow the news and keep up to date with what's going on in the world, so I am familiar with Britney's custody travails, the trouble with the FISA bill in Congress, the baseball playoffs, and Tony Romo's FIVE interceptions this past Monday night. But I admit to knowing next to nothing about this "genocide bill" that Congress is trying to pass right now, wherein apparently we take Turkey to task for committing genocide in the early 1900s. Turkey is all kinds of pissed off at us about it, and is threatening all kinds of mischief, including invading northern Iraq. (I would imagine that they'll also probably pass a bill taking us to task for that whole genocide thing we did with the Native Americans in the 1800s.)

So I ask: why are we doing this right now? What is the point, exactly, in passing a bill saying that some country committed genocide 100 years ago? What does it accomplish? Not saying we should be flippant about sins of the past, but how exactly is Congress going to do anything other than piss off a supposed ally by doing this right now? I'm not playing devil's advocate, I genuinely have no understanding of this particular issue.