GPRS Shield Questions

I have some questions on using the GPRS V 2.0 Shield.

  1. Is the shield compatable with AT&T go phone SIM Cards?

  2. Is the SIM900 Certified by any cell phone carriers, for example Sprint, ATT, Verizon?

  3. If the SIM900 is certified does that cover the GPRS 2.0 Board?

  4. If I put together a system using a Netduino and a SeeedStudio GPRS 2.0 Shield is it covered by the SIM900 certification?

Answers to all or any of these questions are inportant to an ongoing development project for one of my customers.