The possibility someone is able to ddos a lot of the master nodes, and has the funds to run a lot of them them selves is highly unlikely or even impossible.
A more feasible scenario is someone setting up 5000 nodes at once... Oh wait there aren't enough coins for that ;-)
This is right. Pretty difficult to take down 900 MNs in the network. There are protections built into the standard satoshi client.
Ozzie you are my advisor when it comes to these things, if you think I should move away from a VPS setup or I need to bolster the hardware/protection in anyway just let me know mate.
At the moment I'm still struggling with my connection at the warehouse and DOA for P2Pool, it shoots up to 20% whenever I'm using the connection for other things so I'm pretty close to getting a better connection. If that happens I can get some hardware firewall loving happening and there is potential for me to host my nodes with actual hardware as opposed to a VPS provider.