As hard as it is to believe, Microsoft has until now never put out a 3G/4G Surface tablet. But we knew one would come eventually: the company said it was working on an LTE-enabled Surface 2 and indeed, the thing recently surfaced (har) in FCC documents. Now it's finally here: Microsoft just announced that the LTE Surface 2 will go on sale tomorrow, and will be compatible on AT&T's 4G network here in the US. (Fun fact: its official name is literally "Surface 2 (AT&T 4G LTE)".) All told, it'll sell for $679 with 64GB of built-in storage. That's a $130 premium over the 64GB WiFi-only model which, if you're paying attention, is the same premium you'd pay for a cellular iPad over a WiFi one (it's worth noting, however, that the 4G Surface 2 is considerably less expensive).