Fortunately for all the Galaxy Nexus users, the CyanogenMod team has just released a preview build of CM10 for them. While the Samsung Galaxy Nexus can be already updated to Android 4.1 Jelly Bean, many still prefer CM10 because it comes with more features and the ability to customize your device better.
Sometimes CyanogenMod is even more stable than stock ROMs, though it’s not the case yet for CM10, which is still in its very early stages. The custom CM10 ROM is still not very stable and there are a lot of features not working, though it’s worth giving a try to see what you can expect.
CyanogenMod is based on AOSP, so it does not come with Gapps, so you will have to install them separately. Also it does come with a lot of bugs, which may not be reported to the CM team, as they know about most of them and working hard on fixing.