The Dell Aero will be released by AT&T. The Dell Aero is a GSM cell phone and can be unlocked using an unlock code like most SIM based phones can. Once unlocked, your Dell Aero should work with other phone carriers other then just AT&T, such as T-Mobile, etc. I have not tested the unlocking instructions in this article yet, because I have not gotten an Aero :(.
Firstly, you can get a free unlock code by calling up your phone carrier (AT&T) and requesting one. In exchange they will need your Dell Aero’s IMEI number which you can acquire by typing *#06# and hitting enter. Now follow the free instructions below to unlock your Dell smartphone:
How To Unlock Dell Aero
1. Power on your Dell cell phone with an unaccepted SIM card in.
2. Enter your 8-digit unlock code you attained earlier.
3. Your Dell cell phone should be unlocked and may automatically reboot.
You can learn more about the upcoming Dell Aero by reviewing the full specifications here.