Samsung has actually fulfilled their promise to us from last year, they told us that they would update as many phones as possible in 2012 and most people did not believe them.
Well here you go, an official ROM for Ice Cream Sandwich is available to users. This ROM is not a 100% working ROM, in fact reports say it has had some trouble booting past the kernel screen. Thankfully ShabbyPenguin, a developer, has fiddled around to fix up the ROM. This ROM is a pre-rooted ROM so there is some hassle involved when downloading it.
The WiFi, 3G, and 4G seem to have been successful but there are some issues with force closings from the keyboard and MMS.
qbking77 also has some videos demoing the ROM.