Today, FamilySearch.org added more digital images to its Michigan, Probate Records, 1797-1973 collection.
A lot more counties have been added now but remember not everything is digital and online yet. One good thing is that this time is that FamilySearch seems to have digitized some of the index books. The index books are needed to figure out which estate file number is the one you seek.
Remember each county varies in what is available. Use the FamilySearch catalog to determine what records were microfilmed for the county you are dealing with and to figure out if more digital images are likely to be added later.
Good luck manually browsing/searching these digital images.
Oh, and remember these records are free.
See you soon at the Mt. Clemens Public Library!