[BubblePuppy]

First the unofficial Samsung ICS AT&T Galaxy SGII release/leak, and now the first official AT&T SGII CM9 nightly release.

The CyanogenMod team has done it again, bringing their CM9 build for AT&T's variant of the Samsung Galaxy SII to nightly status, and releasing the build to the CyanogenMod mirror network just yesterday.
The build actually released just before news that a seemingly official (and fully TouchWiz-ed) build of ICS had leaked for AT&T's SII, so SII owners have a couple of great options to satisfy their Ice Cream Sandwich cravings. To grab the first (and latest) CM9 nightly for the i777, just follow the link below.

http://download.cyanogenmod.com/?device=i777

Definition: A "nightly" is a bleeding edge release that is built on a daily basis, usually at night after a full day's worth of new code has been committed.
It could oftentimes be unstable and not properly tested, lacking any changelogs, but eventually evolving into alphas, betas, release candidates, and finally stable release.

NOTE: The usual warnings still pertain such as this could brick your phone (very unlikely), it will void your warranty, there may/will have bugs.
Read the rooting and installation instructions very carefully.

For instructions: http://forum.xda-developers.com/forumdisplay.php?f=1304