Its my thought here that the only way you could get them both on at once (assuming this is your end goal) you would need to radios (the cellular components of any phone). We can by phones with dual radios that will connect too two gsm systems and I think any good china brand grey market phone comes ready to roll for this. But the droid pro has only the one radio built in and all though its a world phone can only connect one at a time.
Well thats my guess here, Currently a HTC user but as we speak my Pro is traveling my way! Very exciting!!
"People not things effect change."
Steve needs to learn this, ditch the iPhone for an open world.
Android - Linux for the people.
The Techno Mage
Moto D PRO | HTC DhD | NOOK COLOR cm7bt