If you are tired of that low res, washed out boot animation on your Galaxy Nexus (or really any Android Phone), its easy to change - provided you are rooted of course.
In ICS I believe there are 2 locations for bootanimation.zip files to be installed. The "factory" location is under /system/media/ and the alternative is under /data/local/. Even though the system/media location is the stock/factory one, the data/local one overrides it. I have run half a dozen bootanimation.zips on my Nexus with no problem....just delete whichever one is in the data/local folder and paste in a new one. This allows you to keep the stock one intact in case you ever want to go back to it (just delete the data/local version). Oh, and if you are one of those people who constantly change ROMs and wipe/reset your phone, the data/local file won't be erased whereas the system/media will. So, there's another reason to use the data/local location.
There are a couple of ways to load a custom bootanimation. Some people package their animations as a zip installer that you have to run through either recovery or Clockwork, but I think that adds quite a bit of unnecessary time. I prefer to just copy the bootanim.zip file directly to my phone storage. Quick and Easy.
Note: If you find a bootanimation you like, but its setup as a zip installer, its simple to extract the bootanim.zip. The installer zip will have a name like "fireworksbootanimation.zip". Just open the installer zip, open the 'data' folder, open the 'local' folder, and copy the bootanim.zip file within.
I found this thread on Rootzwiki that has a BOATLOAD of custom boot animation files. I mean, there's a million of them including user requests. Its 50 pages long but worth going through if you have the time. There are also a whole section dedicated to boot animations including things like NFL and NHL Team Themes.
If you are the creative type, you can even make your own. There's a nice tutorial here on how to do it.