Keep up the good work tux, moving to a service that claims to be protected against DDOS. I'd of not expected it either.
Would it not be more wise to transit MTGox across multiple servers and ISPs. Having it running for example on SLICEHOST/Amazon in silent then on times where under DDOS attack or Physical prevention, the exchange can throttle up the "cloud" hosting.
The bitcoin community puts great responsibility on your toes it seems.