The Nexus One Android 2.2 FRF72 build finally leaked, it's an update from FRF50 stock to FRF72. However many of us are running a rooted FRF50 and therefor can't use this.

This update should be able to apply to any Nexus One FRF50 build, but I only tested against Paul's no-preq update. Wipe is not required. Do a nandroid backup before flashing. I'm not responsible for any problems or data loss.

FRF72_from_FRF50_rooted_KB_20100619-signed.zip 40MB. MD5: e52c58021ffa31e8e87d1e9e7d7fdb66

Discussion here:
XDA Developers - Nexus One FRF72

For those interested, I made this by downloading the FRF72 leak, unzipping it to get a list of all the files changed, however these are patch files. Then I reverted my phone to FRF50 stock and flashed the stock recovery and applyed the FRF72. Then flashed Amon_RA recovery and did a nandroid backup. Then used unyaffs to extract all the files from the system image, then wrote a little script to organize only the files that patch files existed for (plus the full boot.img). Then zipped and signed and here's the result.