Who could tell me if Michigan recognizes out of state Domestic Partnerships?

First, if you live in Michigan, Michigan law applies, if you don't, it probably doesn't. If you do live in Michigan, the state recognizes common law marriages from other states but probating an estate if you are the property owner and the suvivors seeks to assert claims can be difficult. If you love this person, have will or trust for their benefit. The cost is small but the amount saved in future lawyer fees and peace of mind for both of you is probably worth it. Good luck.