If you are new to this, a Release Candidate is a ROM version that is considered mostly ready for use. There will be a few bugs and issues here and there, but the ROM is at its final stages and should be stable enough to use as a daily driver.
No, this is not based on Android 4.0, Ice Cream Sandwich. The CyanogenMod team has added some improvements and fixes from the Android 4.0 software, though. Aside from this, there are many bug fixes and new features included. One of the most important fixed issues is the vanishing ringtones from the SD-card.
As it goes with such topics, there is the usual disclaimer. Flashing a ROM requires root access and may harm your device and/or void your warranty. Please be careful and do your research before performing any of these tasks, as the responsibility will fall on your hands if anything goes wrong.
With that said, head over to CyanogenMod’s site to see the list of supported devices, as well as the equally long changelog. If you are still ready to enjoy CM 7.2 RC1, head over to their mirror network to download the files. Happy flashing!