I was in the same boat you are in - I am going to UOP in july 2008 and wanted to be granted the 3 year AF scholarship. I started applying for it in late January (which is indeed late to apply). There are a lot of people in front of me for the scholarship (the AF gave all of their scholarships away already and hope to get more in) so even if they get more scholarships in, it is unlikely that they will get a whole load of em in so that I'll get one. Unless a get a miracle call saying I got a scholarship, my only option is to accept a 2 year scholarship (you pay for the first year), and still serve 3 years (there is a 3 year min).
SOOO what I did is now I am applying to the Navy b/c they still have a lot of scholarships left... and I am really happy that I did. The Navy is amazing and you should consider it for sure.