Bitcoin has some intrinsic value -- but unfortunately, most of this value has the most impact on those doing illegal or unethical things. The ability to control and move them across the globe, nearly instantaneously, with no restrictions or fees, and without the ability of any government/bank to stop/freeze it, has produced quite a market for it (and it can be anonymous if you know what you're doing). You say it has no value, but what about Wikileaks who have had 95% of their assets and income cut off by governments and banks freezing their money. They'd still be 100% functional if they were dealing in BTC. And of course, the drug trade benefits too. These aren't the most "ethical" reasons for it to have value, but they don't have to be good reasons to impart actual value. The fact is, there are people who want BTC, and as long as there's a scarce amount of it, it's going to acquire value in the minds of some. (BTW, I have no interest in these unethical properties, I'm all for BTC because of the fact I have control over it, and don't have to pay anyone or give out any information to use it).
To those arguing about bubbles -- I'm interested to see how this exactly looks like a bubble. Bubbles burst, BTC didn't. The fact is there's still lots of people involved in BTC, there just happens to be more people selling than buying, which is why the prices has declined slowly over months... it didn't just collapse in a week like most bubbles.
Personally, I'm happy to see all the speculators get out of BTC, and hopefully it can maintain some degree of stability now without all the gambling. Unfortunately, botnets and Trojans like this are probably the biggest reason for the price decline, as their constant sell-off causes negative pressure on the prices. But what is interesting is that so far no one has actually succeeded at attacking the protocol itself. Sure, individual websites/exchanges get attacked, but the protocol itself remains secure. I think it's worth something that the botnet owners have decided to play by the rules of BTC... because if they could break the system to make a quick buck, they would. But so far there has been $20,000,000+ worth of value in the BTC for many months, which is plenty incentive for every unethical person in the world to break it--yet no one has.
I'm not convinced that Bitcoin 1.0 (right now) will survive the test of time. It's security is great, but it's name has been soiled, and some lessons learned really need to be applied, but cannot be once the beast is set in motion. I wouldn't be surprised if it stuck around for a while, but even if it doesn't, something else will replace it. There's too much value in "freedom-enhancing" currencies, and there's no doubt that Bitcoin has been a proof-of-concept for it that it works.
P.S. - Bitcoin really shouldn't be referred to as a "currency." It's more like a commodity, similar to gold, since there is a finite amount of it in the world. If BTC is going to survive the legal battles, it would be best for its supporters to not fight for it as a currency, as that can open it up to all kinds of legal attacks.