[jonesle7]

Technically it is possible to activate a Blackberry on a Sero plan. You have to change to Sero voice only and then add the Blackberry data plan; however, it would be a challenge to go back to the regular Sero plan if you decided you wanted to change from the Blackberry to something else.

I'm on a grandfathered plan too and plan to keep it as long as possible. Eventually Sprint will probably require more and more of their phones to be activated on one of their new plans but for now there are still enough compelling options available that I don't plan to switch.