from what i've seen in the past 24 hours both deepbit and slush's have been ddos'd, there was a post about it somewhere, essentially they both make up over half of the current mining pools out there..
yet at the same time both of them were down the network hashrate was actually about the same... was quite odd...
http://www.symantec.com/connect/blogs/bitcoin-botnet-mining i wonder if there is something like this brewing...
it might be time to start having pools use tor or something...