We were in the same boat for San Diego market with 3G accepted work in 4th quarter 2012. On the sponsor maps, Phoenix has many sites 3G accepted. It is a matter of plugging in the 100Mbps+ fiber from Cox or CenturyLink.
My prediction will be summer 2013 you will start seeing sites with 4G LTE. Cox and CenturyLink are faster than AT&T when it comes to delivering the back-haul.
This a comparison of Cox and AT&T in San Diego market. If we had more Cox fiber area's, I think we would had more LTE sites live.