Speaking of CMAS, the people behind the A.W.A.R.E. (Alerts, Warnings & Response to Emergencies) blog put together a nice post that links to info from the major mobile carriers regarding CMAS. Among other things, you can find lists of the models of mobile devices that will support CMAS.
Beginning this spring, new mobile devices are to be shipped with CMAS capability, but many are already in the market. By itself, availability of the devices doesn't mean the system is 100% ready for local authorities to use. See our recent post on efforts to establish new CMAS pilots. The post gives an overview of what it will take to move toward real CMAS use. But, availability of the devices is certainly a sign of progress.
As you probably know, CMAS is the Commercial Mobile Alert System, one of the alerting systems made available through FEMA's IPAWS (Integrated Public Alert and Warning System) program. It will give federal, state, and local authorities ability to send 90-character text alerts to mobile devices in a specific geographic area without requiring the public to sign-up.
All the best,