Each new attack, and I expect many more to come, will make the currency more reliant. And if a weakness is found that the Bitcoiu community cannot fix, and it breaks the currency, good again.
For whatever crypto-currency must take over as the next form of money, it must take on the job of being reliable enough for all of humanity to use.
There will always be enemies of anything, always people looking to cut down a competitor.
Unfortunately for me, I was not able to verify my coinbase.com registration due to this attack, so I'll keep trying. Once bitcoin emerges, I'd like to get some Bitcoin, litecoin, Ripples, and Quark.
More power to the community who must rally together continually for years to come to over-come assault. Bitcoin has the unfortunate responsibility to lead the other crypto currencies to solve these complex technical challenges.
There are two possible reasons for the attacks, one could be people who want bitcoin to fail.
The other, I think more likely, is opportunists who want to drive the price down with fear for them to buy for the next leg up.