According to LG’s Facebook Page four of their premium Android handsets will receive an upgrade to Android 4.0, Ice Cream Sandwich, they are:
LG has said that this is not the end all to their Ice Cream Sandwich updates. They are still determining the compatibility of some of their other phones. There is no word on whether the U.S. variants of each of the named devices will get Android 4.0. They are the T-Mobile G2x (Optimus 2x), Sprint’s LG Marquee (Optimus Black) and the AT&T LG Thrill (Optimus 3D). Most likely all three U.S. variants will get Ice Cream Sandwich but we suggest you stay tuned to LG’s Facebook page here, to see if your phone will get the upgrade.
Source: LG Facebook