The LTE hardware was spotted in a teardown by AnandTech. Getting it to work, though, wasn't clear. The hardware necessary for LTE on at least some of its bands, namely 1 (2100 MHz), 2 (1900 MHz), and 4 (AWS 1700/2100) is available.
However, Telus users in Canada have managed to activate LTE on their network, and as proof, we have a video embedded showing that they can indeed get a true 4G (as opposed to faux 4G HSPA+) connection working.
To enable the capability, you must access the device's test menu, by dialing "*#*4636#*#*". Then, tap on the preferred network type option, where you can select either LTE or a mix of LTE, GSM and CDMA. According to the video, the Android phone then accesses LTE on your carrier's network if it supports LTE Band 4.
In the U.S., Verizon uses the 700 MHz band, but does plan to move into the 1700 / 2100 MHz range. AT&T uses 700 Band 17 as well as Band 4, but Band 4 is less common. T-Mobile USA, while trailing the pack among the Big Four, does plan to use Band 4 for its LTE service when it rolls it out in 2013, so that's good news. Of course, by then, the Nexus 4 will be obsolete.
The LG Nexus 4 is Google's latest Nexus device, and was the first smartphone to ship with Android 4.2. The device is sold on Google's Play Store for $299 (8GB) or $349 (16GB). It sports a 4.7-inch 1280 x 768 WXGA IPS screen, 2GB of RAM, a Qualcomm Snapdragon S4 Pro APQ8064 quad-core 1.5GHz processor and an Adreno 320 graphics processor.
The device also has an 8MP rear-facing camera and a 1.3MP front-facing camera. Sold unlocked, it does not have a microSD slot. It is currently sold out in the U.S. Play Store with no date given for a "return."