Rahm Emmanuel has been struck from the ballot for the Chicago Mayoral race:

A state appeals court on Monday threw the Chicago mayor’s race into turmoil by ruling that front-runner and former White House chief of staff Rahm Emanuel did not qualify for the February ballot.

Emanuel immediately responded that he would appeal the ruling to the state Supreme Court and urged quick consideration. The ruling on Monday overturned decisions by a lower court and a Chicago elections board that allowed him on the February 22 ballot.

It appears that there is an exemption in the law for elected officials, but not for staff, and the fact that he had rented out his house was a major contributing factor.

That being said, I think that it is likely that it will be overturned on appeal by the Illinois Supreme Court, though I would prefer if the ruling stood, and Rahm has the  backing of the machine, so he still has a good chance of winning.