So today was the first day to sign up for the MSC for May, the place opened at 8, I called at 10:30. They were already booked and I am third on the reserve list! My question is what are my chances of actually getting into the class?

Actually it's not too bad. Your chances are pretty good that three will not show for one reason or another. Just show and see what happens.

when I took it, we had 24 spaces and I think 3 reserves got in.  People change their minds or life gets in the way... show up for the class... you've got a good shot at getting in.  

ditto here, I think all the reserves got into my class last summer too.  Also, did you print out the whole schedule.  I didn't realize that they run them all the time not just weekends.  I took mine over two weeks going mwf nights.  it wasnt' too bad. just hot the end of july.

jake