If I read the processor specs correctly, the MSM6500 in the 8703e is not capable of leveraging EvDO Rev A. If that's correct then to make the 8703e work with the new Sprint Q Chat would require changes to both the hardware and the software. I can't imagine the hardware specs changing mid-production.

BG has suggested that we may see a CMDA Pearl as early as Spring '07 (I'm skeptical ...). Considering that, A) a new peice of hardware is needed to leverage EvDO Rev A in order to implement Sprint Q Chat, B) there are already rumour about the Cingular Pearl having PTT functional, it stands to reason that a CDMA Pearl might be the device to look at for PTT on CDMA networks ...

That, of course, is HUGELY speculative ...

And again ... everything I'm hearing from RIM suggests that (at least for CDMA carriers) we'll see a CDMA/GSM hybrid before we see a PTT enabled device.