We here at RKG hit the "migrate" button too quickly. Now have some heavy lifting to get our RSS working again. (Perhaps we'll drop FB until it works?) We're not alone: the phrase "google feedburner transfer broken" returns 37K hits on Google today.
Apologies to all our readers experiencing disruptions due to FB/Google server problems. What a mess.
Feedburner users: we recommend delaying this migration as long as possible, until the process works.