hi,
NO these cards are (luckily) not locked.
I got the iTalk deal with the E620 + laptop, and it works fine with MTN, Voda, or VM sim inside (VM sim must be newer 128K though, 64K not working).
One of my users got the R49 deal, also not locked.
Seems locking is stoopid nowadays, as they'll have to unlock again when number porting becomes available.