While the Android 4.0 Ice Cream Sandwich update has yet to officially make its way to the Epic 4G Touch (or better known as the Galaxy S2) on Sprint, it seems that for those impatient, an experimental build of the CyanogenMod 9 Android 4.0 ROM is currently available for the Epic 4G Touch, although given its experimental and early stages of development, it does not seem like a good idea to use it as a daily driver, but if you're curious and wouldn't mind giving it a spin on your Epic 4G Touch, the download and instructions can be found on the XDA forums and RootzWiki.
Ubergizmo, Sprint's Epic 4G Touch receives experimental CyanogenMod 9 build