Didn't watch this, but going by the National radio broadcast (westwood one), the said that hit that hurt Willis looked unintentional, that they both unfortunately moved the same direction when trying to avoid the dangerous contact.
Without seeing the game for myself yet (hope it is replayed), I have no dog in this fight.
I will say though, that I have a hard time sympathizing with any Ravens players on this. When you put bounties on players, you can expect that the opposing team is going to hit you just a little harder when they meet up.
This is a league wide problem though, and as Jscott said, Brian Dawkins is the worst of them all. I would have suspended that jerkoff on many occasions throughout his career.