This leaked build is now available for download at the DROIDRZR forum and can be applied via the stock recovery like any other update file; however it would not be wise to do so unless you know how to revert back to Gingerbread if needed.
Motorola has promised the official Ice Cream Sandwich updates for Droid Bionic, RAZR (both versions) and Xoom. Xoom Wi-Fi has already got the ICS update in US; other versions will soon get it, which should be followed by RAZR.
If you do apply the leaked update, let us know about your experience in the comments below.
