For this week, I am still on CM9 ICS ROM for my AT&T Galaxy S2 SGH-i777. I’ve updated to the latest nightly with on-screen buttons so you will have the ability to use the home button. There’s couple other ICS ROMs available at the moment but I believe CM9 ICS ROM is still the best so if you want ICS on your AT&T Galaxy S2 SGH-i777, I advise you to stay/install CM9.
Try it out and let me know how it goes for you!
*Note – To flash the on-screen buttons you must at least boot once to your ROM after installing then re-install on-screen buttons with CWM.