Verizon's definitely sending out the 4.0.4 update to its Galaxy Nexus customers, as noted earlier today. But it appears they're taking their sweet time about it. If you're still running the official 4.0.2 release, you can click here for the official download of the updated ZIP file. It's about 40 megabytes, so even those with tiered data plans should be able to grab it without issue. You'll need to be rooted and running a custom recovery to apply it.