Justin Jackson from Maryland declares, and he will have an agent.
There have been a handful of those that are going to test the waters without an agent as well. Two for Nebraska and Edwards for Purdue, but I don't know how meaningful that news is.
For Michigan, if Mo were to stay, they would have to do something about a scholarship next year. I suppose one of the current five signees could gray-shirt or do prep school for a year. A couple are raw and young for their grade. There is a distant possibility of transfer out, but that is unlikely. Your most likely suspects would be Brooks, Watson, Davis, and they are all getting spot minutes and really just starting to the development curve with Beilein.