Going through the same decision here!!!!
I myself am an Apple Authorized Service Provider and have been for about 5 years. I have actually been in business for 7 years, but it took me almost 2 full years to get the AASP designation. Apple really put us through hell to get it. We had to beg and plead with anyone who would listen becuase the closest AASP's to us at the time were some 50 miles away. Which at the time was considered coverage. Anyway...
I myself have been considering doing this for quite some time. Even though I have proven track record and 700+ Clients, that will not exempt me from probably going through the ringer to get a dealership.
I guess I am writing here becuase I am also interetsed in what people will say. I do know, as was mentioned above that Apple does require 100K sales of Just Apple Products as part of thier agreement. I also know that you have to have a good line of credit with either Tech Data or Ingram micro.
Anyway, if you do go for it, maybe you could let us all know how it worked out.