We'll likely get a new iPad 3 sometime this March and an iPhone 5 later this summer or fall, but will either or both of them run on the new, ultra-fast 4G LTE (Long Term Evolution) networks? And if they do, will LTE be built into every device, or will there be special models made for just those networks that support it?
Right now there's only one iPhone 4S and it runs on both GSM/HSPA+ and CDMA/EVDO Rev. A, on every carrier that offers it. That's a change from the iPhone 4 that debuted as GSM/AT&T only and later had a different model, with a different antenna, released for Verizon. Likewise, the iPad 2 still doesn't come in a unified model, having on version for AT&T/GSM and one for Verizon alone.
So, while Apple has moved to unify their manufacturing for iPhone 4S, they have in the past, and still to this day, made separate models of iPhone and iPad to handle different network technologies.
And they could do it again for LTE.