As long as the black market websites running through the TOR network exist, this currency is going to be the 'weapon of choice', so until mining catches up with the difficulty of 'solving' to bring more into existence, prices will probably increase. Don't get me wrong, there are myriad legitimate uses for this novel currency, but criminals are sharp when it comes to adaptation, and what you have here, with a peer to peer system, is something which makes law enforcement's job VERY challenging for any serious criminal.
In the old days (12 years or so back), international cyber criminals paid each other globally via Western Union. That still required the sender to appear at an agency, fill out paperwork, and be on camera - and give away their physical location (or at least, somewhere within travel time of their operation). They had to know their recipient's geographic location, even if they 'receiver's name was made up, and he too would have to appear to pick up his currency. Sender transmitted money transfer control number, receiver provided same, money dispensed. Typical law enforcement methods (eg physical surveillance) were very, very effective with this. AUSTRAC also mandated photo ID with every transaction - not hard for a criminal to acquire, but another layer of hassle to remain anonymous. Enter digital currency en masse.
I was a customer of e-gold. I'm one of about 22 out of several thousand users who successfully contested a US Federal Government criminal assets forfeiture order late last year. I liked the idea of being able to invest in gold in increments which I chose (keep in mind, I was quite a bit younger then, I like my assets more tangible now). As it turned out, the Russian mafia and credit card scammers, who used the system to move money without the hassles of regulatory oversight, rather liked the system too. So too did peddlers of base and vile wares such as child pornography. Australia simply banned market makers from operating in Australia. The system has, several years later, come apart in court, because of the centralised nature of how the transactions were conducted, and the need for those accounts to need something akin to identification. Sure, thousands of accounts ended up being created by criminals using fake or stolen information, but they had to do so.
Not so with BTC. You can create a bitcoin 'wallet' as easily as entering a URL. The central server confirms the transactions but doesn't regulate them, and merely traces a path, which, if you know how to cover yourself at the end of said path, leads absolutely nowhere.
End of the day - where there is supply, there is demand. Flawed or not, bitcoin is the currency of choice for the new digital underworld. Demand will persist until this is crushed or something else better appears.