As of right now it looks like mtgox is suffering another DDOS attack. Also Seals with Clubs (the largest bitcoin poker site) is suffering a DDOS attack as well and appears to be down. Kinda sucks because I was down to the last two people in a poker tournament on SWC , will be interesting to see if they just take my buy in money, if i get refunded, or i get the prize money since im already in the prize money.
Seals with clubs has not been targetted or DDOS. They were on cloudflare and cloudflare has been DDOS for their support of SPAMHAUS. The largest DDOS in the history of the internet actually but it had nothing to do with bitcoin.
http://blog.cloudflare.com/the-ddos-that-knocked-spamhaus-offline-and-ho