its could also be see as a "compliment" of sorts, that you have a site worthy of some botnet attention.
i would hazard a guess at the attack was/will/is being co-ordinated by someone who is pissed off @ se-nse in general, a user,
maybe some UK cell owner with links to worldwide underground programming group ( definatley not on irc) (botnet not controlled via irc either?) who all congregate in say 1 place (known only to them) using some obscure p2p or chat protocol for communication, but all them people are individually into all kinds of things, like anyone is, but they get rubbed up the wrong way by some n33k online,
so they jump over to obscure protocol p2p, communicate the www and or IP of cheeky/annoying/disrespectful persons they have encountered, so some person on the other side of the world logs in to his (homemade) control panel, verify they are the botmaster and type IP, click "go" and up to 50.000 machines all over the world start to request things from the server that it just hasnt heard of, or just cant answer fast eneough so takes timeout.
and this isnt going to get any better anytime soon, as home connection speeds (upstream) are ever increasing, knowledge is more available, anyone can have broadband, trojans get more sophisticated as do the methods of deploying them, and people will always get pissed off. its just life, and even if you had the actual IP of the person resposible not one thing would happen to them if you reported to their isp their activities, as the isp's just send a warning email saying such and such activity has been coming from your IP etc, you reply with thanks as their email alerted you to the fact that you were "infected" by a trojan which was participating in therse terrible deeds, i know of one case where the isp dropped the customer and that was because he took out his own isp
and that was in romania lol,
did you also know that online credit card fraud is not a reportable ( to the police) offence in the UK!! point being their is a really really large amount of things that take precedence when it comes to taking action against almost untracable denial of service.
my 2p worth.