The Verge:

The Verge has confirmed with Verizon Wireless that the iPhone 5 won’t support the feature when it’s on the carrier’s cellular network, even if it is connected to LTE. Since Apple says that Sprint and Verizon will be offering the same version of the iPhone 5, it’s safe to say that simultaneous voice and data will not be available on Sprint’s network either.

Well, that sucks and might be a dealbreaker for some folks looking to switch from AT&T.