[michaelk]

http://en.wikipedia.org/wiki/Evolution-Data_Optimized

The EV-DO feature of CDMA2000 networks provides access to mobile devices with air interface speeds of up to 2.4 Mbit/s with Rev. 0 and up to 3.1 Mbit/s with Rev. A.
...
the new Qualcomm Rev. A modems can maintain both circuit switched voice and packet data calls from the same radio

so sounds like technically it would be a possibility