I haven't seen him play football yet, whats to celebrate? 
See a movie called "42". That may clear it up for you.
I think what we are celebrating is the courage it took to openly acknowledge personal information that he knows, from life experience, will put him in the crosshairs of the loudest and most virulent haters. Michael Sam has the background credentials, size and skill set to step into an arena where paychecks have a lot of digits. He's risking all of that by not hiding in the closet. How can you see that as anything but a daring roll of the dice?
He's betting, hoping, praying that America has evolved sufficiently on this issue. I'm proud of him for doing so. And a lot of other people are too.
http://www.msnbc.com/msnbc/michael-sam-supporters-standwithsamIncidentally, Michael Sam was chosen SEC Defensive Player of the Year on a team that won the Cotton Bowl. So, yes, he can play.