As soon as Google announced the availability of Android 4.1 Jelly Bean, the CyanogenMod team promised the availability of CM10 based on the new platform release.
CM is one of the most popular custom software for Android devices out there, and many are already eagerly waiting to get it on their units.
For some Galaxy S III
users, the wait is over, though with a caveat. Only preview builds of CM10 can be downloaded at the moment, and they are buggy.
However, things have started to move in the right direction, and more stable builds are expected to become available in the not too distant future.
In the meantime, those who would like to grab the early software release should head over to this thread
on XDA-Developers for the SGH-I747 (LTE) downloads, and to this thread
for the T999 bits.