It's kin of a necessary market correction to lower the price. If the mkii price was kept at near $2500, then the used price would be artificially high. People with 2 year old mkii's, and thousdans of shutter clicks would take their real value 1400-1700 bodies and sell them for 1800-2100 - which, some may balk at cause they want that extra cash so they can afford the mkiii - nevertheless it would still be an artificially high used price.
Also, I don't really think this validates any of the rumored prices (IE $3500 body only/$3500 with kit lens). This news really tells us that some of the previous rumors may not be true - IE that canon intends on continuing the mkii line. They liquidated during the holidays, then kicked up the price to try to make margin goals, now, they need to clear space - so boom, the price drops. OR, ya never know, maybe they will continue the mkii line for a year, with a $1999 tag many crop users will take a good hard look at the mkii. and if the specs and IQ are spectacular for the mkiii, then those who go for a reduced price mkii may very well pony up for a mkiii next year..
Either way, yes the mkii is a fine camera, but it is an old camera and there is really no justifiable reason to keep the price so high in the face of the new model.