The 5 year contract COULD be for maintenance.. I believe the system is already in place.. I put the ev-do PRL on my phone, and it showed me as receiving the signal, but I cannot call or connect to it.
I'm inclined to agree with jammis, the technology is there... likely shared with verizon, sprint, and/or alltel, but cricket just signed a service contract.
Just my $0.02. I don't know crap, and could be COMPLETELY wrong.