On National Signing Day, you really should expect the unexpected. Just look at what happened with Detroit running back Dennis Norfleet in the last day. On Tuesday morning, he was quoted in a Detroit News article as saying that Michigan never even gave him a look. By early Wednesday morning, just as National Signing Day was getting started, he had decommitted from Cincinnati to the Wolverines.
The talk of Tuesday for Michigan football recruiting was about a possible surprise commitment on National Signing Day, and that is exactly what happened with Norfleet suddenly joining the 2012 class after not even really being on the radar. While this is more proof that anything can happen, the expectation is that Norfleet's commitment fulfilled the quota for surprises for the Wolverines. There isn't expected to be any activity beyond Michigan's 25 commitments signing their letters of intent and officially becoming Wolverines.
For Michigan, things should actually be relatively quiet until Friday. That is when Chicago offensive tackle Jordan Diamond will announce his decision. He recently narrowed his list of schools down to Michigan, Wisconsin, Arkansas and Auburn, and we will find out what his choice is in a couple days.