Most likely it is being ddossed... by people trying to sell, but that's just my opinion.
There were many, many transactions with amounts of 0.02 BTC. I think P(attack|0.02 BTC * n) > P(~attack|0.02 BTC * n). The reality is probably six of panic sale, half a dozen of DDOS.
The thing with small BTC transactions is that it's more likely to be someone trying to prop up the market, not someone trying to DDOS it. Every time the price starts to go down you start to see a lot of very small buy transactions at a round number a fair amount above the current sell price start going in. The only reason for them appears to be just to keep the displayed "last sale" price on MtGox high.
Likewise, Mt. Gox made mention of "Being DDOS'd" at certain points, but I'm a little skeptical of the claim given that their own charts show a huge jump in trade volume at around the same time.
So no, there's no real "proof" yet of it being a DDOS or just lots of panicked traders, just lots of speculation (heh, heh).