Microsoft said that a Surface 2 with LTE was coming to AT&T early this year, and it now appears that this cellular-equipped Windows RT tablet is finally close to launch. The company has just received FCC approval for a "portable computing device" that sports the Surface's familiar 10.6-inch display as well as AT&T-native LTE and HSPA data. The filing doesn't hold any surprises, then, but it suggests that there are few obstacles left to releasing the 4G slate in the US. Given past promises, we wouldn't be shocked if it launches within a matter of weeks.