Update: Here's an official Google Support answer stating the GNex will indeed be stuck in 4.3-land for eternity.
At the bottom of Google's official Android 4.4 announcement post on the company's blog, some rather pertinent information for current Nexus / GPE device owners is thrown in: OTA update news!
KitKat will be coming to the Nexus 4, Nexus 7 (presumably both models, but not explicitly stated), Nexus 10, and the Google Play Edition Galaxy S4 and HTC One. Those updates will be available in, you guessed it, "the coming weeks." Absent from the list, as some expected, is the Galaxy Nexus. The Galaxy Nexus was the world's first Android 4.0 smartphone, and its fate after an update to Android 4.3 was certainly up in the air for a while there. Many pointed out that while Android 4.1 was a major update, 4.2 and 4.3 were much more incremental, and that for that, Google may have given the GNex one last hurrah on the OTA list. Sadly, that doesn't seem to be the case, though it's understandable, considering the company that made the chipset for the device has since gotten out of the mobile business, Samsung seems pretty much out as a Nexus partner, and the phones themselves are getting pretty long in the tooth.
We're working on our Android 4.4 overview post, but in the meantime, be sure to check out the Nexus 5 announcement post, and get yours before they're gone!