[MOD][Update: 12-Aug-2011]Rooted CG from CH Leak
Thanks to dangpzanco for the GREAT IDEA.
I finally got my Rooted GB working here. I can't provide a download link now but I'm going to do it later for sure.
Apparently there was a final signature check that was done somewhere after mounting the cache partition, preventing me from booting with a pure update.zip on top of froyo /system. Thanks to dangpzanco I could bypass it and get root.
Quick Guide (requires froyo, root and Droid2bootstrapper):
1. Download fixed SBF bellow. It's made from the CH leak containing ONLY: CG35.smg (boot) CG47.smg (recovery) CG61.smg (devtree) firmware.hmg (header) RAMDLD.smg (flash updater).
2. Download root_and_recovery.zip and copy it to SD Card.
3. Download full leaked SBF from General Forum (CH, signed) and use MotoAndroidDepacker to extract all images.
4. Copy the CG39.smg to /sdcard/
5. Boot into CWM
6. From CWM open adb shell and use this command: dd if=/sdcard/cg39.sm of=/dev/block/system
7. Still on CWM apply root_and_recovery.zip
8. Still on CWM wiped everything
9. Boot on bootloader and flash fixed SBF