Unfortunately, on the Z990G "Merit", not yet.
As borked as the firmware is, at least we've gotten this far.
The Z990 "Avail" (The older AT&T 'sister' phone) is MUCH easier, just enter in a code.
The Merit, however, is the "fixed" firmware for this 'family', and thus, made it much more difficult to root.
We're working on both. It will just take time.