I think you may have misunderstood what I was saying here...
A bunch of folks are responsding with "you can have data and voice at the same time if on wifi"
That has always been the case. ALWAYS. CLEARLY the OP is NOT asking about wifi here... which is qhy I point out how silly it is for people to even be mentioning it.
EDGE does not support voice+data simultaneously, for what it's worth.