A few days ago it became known that the Nexus 4 had an LTE chip inside. That got many people on Verizon and even Sprint excited, thinking that there might be a way for the current Nexus 4 to connect to LTE. Wrong. Just because the chip is there doesn't mean it will connect to your favorite LTE network. So why did LG put an LTE chip inside the Nexus 4? Well the most likely reason would be because the Optimus G supports LTE. So rather than making an entirely different board with just HSPA+, LG kept that board and put it into the Nexus 4, which is probably another reason why the Nexus 4 is so cheap.
So could hackers get LTE to work on the Nexus 4? No way. There's a lot more work that needs to be done other than just activating the LTE radio. You'd need specially designed firmware for the radio, and a fresh bundle of antennae within the chassis.
So there's no doubt that we may see a LTE version of the Nexus 4, most likely on Sprint since they've been so cooperative with Google and have sold the Nexus S 4G and Galaxy Nexus very well in the past 2 years. But I wouldn't hold my breathe. Right now that's basically a rumor. But when you look at the past, Sprint has gotten a CDMA Nexus months after the Nexus went on sale. Look at the Galaxy Nexus, became available in November, was announced on Sprint in January as one of their first LTE devices.
Just because the Nexus 4's LTE chip is dormant, doesn't mean there won't be an LTE model coming soon. It just means your current Nexus 4, if you were able to get one, won't support LTE. Which is okay, we already knew for the past few weeks that the Nexus 4 wouldn't have LTE. So this all means that your Nexus 4 is still an HSPA+ device, which is okay for most people. If you're one who needs an LTE device, either wait and see if there will be an LTE Nexus or you'll have to get a different device altogether.