"What is the point of the LTE thing. I mean with the modem, what can you call anyhow?"
The cellular modem in a tablet like the iPad Mini, be it HSPA+ or LTE, is for digital data. That means it won't work for traditional voice or texting service provided by your cell phone company. This difference in cellular modem service is what distinguishes a cell phone from a tablet.
However, a cellular modem will allow voice over IP (VOIP). So if you have signed up with a VOIP service like Skype, Oovoo, or Google Voice, you can send and receive voice calls.
Cell phones keep getting larger. The Samsung Note 2, with its 5.5 inch screen is an example of a phone with a whopper of a screen, and phones with 6 inch screens will be here in the next 6 months.
In a few years, the cell phone carriers are planning to transition away from traditional voice and text service. When they get to near-100% coverage on their networks using LTE, then they can re-purpose the radio spectrum used today for voice and text. The result will be faster service and more value-added features (read: cell phone companies make more money).