If you got 2.2 over the air and lost root or want to get root- I followed these instructions per birdmans advice...
xda-developers - View Single Post - Easier 1-2-3 Droid 2 Root for Windows and Linux (and soon Mac)
I am a complete newb to Android- so if I could do it anyone can. But I take no responsibility for bricked devices. If I had known at the time I did this that I could not recover into 2.1 I probably would not have done it. But I did it and it worked fine.
In a couple of days there will probably be an easier method like "Universal Androot" -but for those that are as impatient as me - I share this.
Good luck -and may the force be with you- always.