What are Dower Rights?
Michigan is a dower rights state which means that a married woman has an equal interest in any property owned by her husband, regardless of when the property was acquired or whether she is specifically named on the deed. For this reason, married men cannot acquire property in their name only if they are doing so with new mortgage financing, inasmuch as the lender will require the wife's signature and name on the deed to perfect their lien. A married woman may acquire property in her name only.
That is from: http://www.weirmanuel.com/buySellFAQ.php#q10
It gives a concise view of dower rights. Now, if I remember correctly and without further investigation, I believe that a woman cannot release her dower rights in Michigan based upon statute.
Concerning the mortgate: both of you will be equally liable for the motgage until the finance company releases one of you from it. Now about the only way this is going to happen is if the current mortgage gets paid in full. i.e. refinanced. Even if you refinanced without your wifes name on the mortgage or deed, she still retains dower rights.

