That may be outdated. I was just able to connect to B.Net and a game no problem. Didn't play through it, but that sounds like it's further than some apparently are.
As I posted earlier in the thread, there really isn't a true way to stop DDoS attacks from coming at your service. The key is minimizing the downtime. The amount of servers required to "handle" a DDoS attack is not worth the cost. You'd have multiple servers that most of the time would remain unused, and those things aren't cheap either. Yeah you can argue that Activision can handle the costs but all those servers and the manpower required to deal with them can escalate costs very quickly.
They may also not all be DDoS attacks. Could just be something is acting funky on their servers, which could also be causing issues that are allowing DDoS attacks to be more potent than normal.