I'm from West Michigan and have heard about the move possibility.
I recently spoke with a family friend who is a businessman in the Lansing area. He has no medical connection, but is someone who pays attention to what is going on. His take on the situation was this: (I don't know if this is accurate, its just what I heard...)
He said that the local Lansing Hospitals had not treated the med school well. When the school asked for "things" (the example he gave was for the school to have their own beds) the hospitals were not accommodating. Basically, they held the med school as a captive customer and were not responsive.
As far as Grand Rapids goes, it is definitely undergoing a major rejuvenation. There is a lot of money (VanAndel, DeVos, Secchia etc.) being pumped into the city and the local university (Grand Valley State University.) These are people with the will and the means to make things happen.
From what I understand, the MSU med school is being presented with a very attractive offer to pick up and move to Grand Rapids.
The aforementioned "friend" hypothesized that the decision to move had been made, but that MSU was taking some time to make the proper political moves before ?taking the school away? from E. Lansing.