This is an early list of who is going to be at the Spring Game this year. This list will continue to grow, since these are only the players I've talked to so far. Some of the visits could change as we get closer, so just remember that.
I'll keep adding to the list as I talk to more people, but here's what I have so far.

Yes

WR DeAnthony Arnett 

OH LB Percy Johnson
OH DE Bryan Baird - Said he will probably be there, not positive.
OH DB Greg Brown (commit)
MI DE Brennen Beyer
MI CB Delonte Hollowell (commit)
MI OL Anthony Zettel
FL RB Demetrius Hart (Mom coming too.)
FL S Dallas Crawford - Yes. This is a big one for Michigan.
FL WR Sammy Watkins - Yes. Also big.
MD DT Vincent Croce - Yes, as of now. 
TX RB Jarrell Oliver (same school as Stonum, Herron, Woolfolk)
NJ LB Antoine Pozniak - He's coming with the "Top Prospects Family." Je'Ron Stokes dad is the founder of Top Prospects Family.
NJ ATH Miles Shuler

PA DE Deion Barnes - 6-foot-5 and 225 pounds. Same school as current wolverine Je'Ron Stokes, and his brother Malik Stokes.

NJ LB Andre Hodge - Top Prospects

Other Top Prospects Family - Ronald Butler, Tyron Stevens, Lamar McKnight

No

IN OL Tony Springmann
GA WR Justin Scott
FL DE Anthony Rabasa
PA DB Kyshoen Jarrett - No, as of now. Family might decide to come, but no for now.
OH S Ron Tanner - He has baseball.
OH DE Robert Mincey - No, he'll be at Toledo. No offer, not sure if he'll get one.
OH DT Kevin Williams -  He'll be at Nebraska, for their spring game. He was recently at Michigan for one of the practices. It seems like it's down to Nebraska and Michigan. He'll make his choice shortly after the 17th

NC LB Kris Frost - No. His family waited too long to buy tickets, so they were too expensive when they went to buy them. He's NOT going to Auburn's spring game over Michigan's, he's going to Auburn's because it's only 6 hours away. He figures he might as well go somewhere, if he can't make it to Michigan. They are trying to find another time to make it up.  

AR QB Kiehl Frazier (2011) - No for the spring game. I spoke with his father, though, and they're really excited about Michigan. He said they DEFINITELY plan on making a trip to Ann Arbor. They really like Coach Smith, and are excited to see Michigan.

NJ WR Damiere Byrd - Track Meets

Maybe

MI RB Justice Hayes is going to try to make it. Not positive yet.
OH TE Ray Hamilton - There's a "strong possibility" that he'll be there. Not definite.
OH OL Aundrey Walker - Doesn't know for sure yet. It's still a possibility.
OH WR Shaq Washington - Going to try to make it. He doesn't have an offer, but Michigan is one of the few schools he's hoping to get an offer from. He thinks he fits the offense really well. 
OL Matt Frazier - Didn't end up making it to practice the other week. He fell ill, and couldn't make it. He's either coming for the spring game, or one of the early games of the season. Most likely a game, though.