I just got the OTA warning and it is downloading the rom!! You guys are awesome.. but, all the text is in chinese, is this supposed to be this way or am I downloading something else? I'm on MIUI Android 2.5.11 and followed the first posts instructions.
I can confirm that the OTA-update for the Sensation works. It is indeed 200+ mb instead of only the updated files, but it works like it should! I've still got all my data and I made and restored no backup.