In the news

What makes the most sense to me: the rebels got trigger happy (the Ukraine claims they've shot down a jet fighter and cargo plane in the last couple of days). My optimistic take on this: Russia is not going to be happy about this, and there could be a very public move by Russia to distance themselves from the rebels, and ultimately, this may hasten the end of the conflict.
The Russians do have a track record for shooting down passenger jets though.

This would make, what, number 3, including Korean Air Lines Flights 902 and 007.

[Edit]

But the Ukrainians also seem to have taken out Siberia Airlines Flight 1812 with a missile in 2001...