Just got my corporate statement today and found the great surprise as well. From our contact at Amex we are told that there has been a "tremendous" increase in "small" point transfers (read as 5000). This has apparently occurred since the CP/AC merger began last year. People are only transferring points in small increments as they need them due to the uncertainty. According to the "inside source" although it mainly affects CP points transfer, they couldn't discriminate and so it applies to the other airlines such as Delta as well.

The 3500 is for "increased costs" associated with the large number of small points transfers.

(I didn't know babies could get credit cards, but with that explanation they must think that we were all born yesterday!)