I too have (HAD) a rooted phone so I followed the first step of putting my phone back to "stock" Froyo. Just a word of caution, I had no problems following the procedure (download driver, ODIN, froyo_eb13,...) What happened when I returned to stock is that I lost all my settings and accounts and apps. No email, no contacts, etc. All my pictures and music seemed to remain intact. There also seem to be some odd system stuff that remained like available ringtones etc.
I did back up my user apps which will have to wait until I get the time to root Gingerbread. I'm not sure if I should have done a "full" system backup then tried to restore the "data" for the system apps (using titanium backup). At this point its too late for me I figure so I'll slowly repair the damage I did. I've got most of my email, calendar and facebook re-setup.
Oh FYI my wife's stock EPIC4G retained all this data when she update to gingerbread so it was clear.y the "return to stock" that did them all in. This is probably obvious but it was 1:30am when I started so I'll claim lack of sleep.
Jim M