"I feel bad saying it but the Nexus 4 feels like an "S" upgrade (like Apple's upgrades)."
First off, don't feel bad saying it. Apple's update strategy has proved to be successful, if annoying for those who want the top-of-the-line phone year after year but grimace at the cost. And there's an argument to be made here, though I'm not sure it quite adds up.
The internals of the Nexus 4 are a significant improvement over the Galaxy Nexus, both on paper and in actual use. Just ask anyone who's tried Photo Sphere on a Galaxy Nexus. The Qualcomm Snapdragon S4 Pro is a huge jump.
Don't discount the improved camera, either. When I'd carry the Galaxy Nexus, I'd also carry a second phone, with a better camera. (Either the Galaxy S3 or the HTC One X.) That's not normal, I know. But that's how bad the Galaxy Nexus camera is compared to those two phones. And with the Nexus 4, I'll not be needing a second phone for proper photography.
Android 4.2 isn't a giant leap over Android 4.1, but there's enough there to keep it interesting, and we still don't know if the Galaxy Nexus will get all the improvements in the Nexus 4.
But maybe even more important is the price. You can get this phone for $299 or $349 unlocked. No contracts. In and out. And if it turns out you can't live with the anemic storage or lack of LTE data on AT&T in the U.S., (remember that there's no Verizon or Sprint-capable version, and T-Mobile still doesn't have any LTE) you'll be able to get most -- if not all -- of your investment back pretty quickly. What's it cost to upgrade to the latest iPhone or manufacturer's-best Android phone year after year?