This is surprising. The Rackspace DNS infrastructure is large and robust. It was believed just the bandwidth to the masters alone should be sufficient for even

This is surprising. The Rackspace DNS infrastructure is large and robust. It was believed just the bandwidth to the masters alone should be sufficient for even the largest DDOS. So this is either something different or of a vastly larger scale than has been seen before. Yeah, no zone transfers, but you can always grab a complete Bind 9 export via the API or just call support and they can fetch it for you.