Cingular doesn't insure any of the high-end phones or BB devices. I assume because they fear people would intentionally "brake it" or have it "stolen" just to get the latest and greatest device on the market. In fact the list is so long, I assume the only thing they actually insure is the free phones?
Btw, the exclusion list doesn't include the 8700c, but I am sure they wouldn't allow it if you called and tried to add it per the note at the bottom.
The following wireless devices do not qualify for coverage:
Note: This information reflects the current list of ineligible equipment as of July 24, 2005 and may vary at the time of your inquiry/enrollment.