Right now, we have an internet "currency" that is difficult (or at least cumbersome) for the average person to figure out. It is hard to move money in and out of exchanges, and history tells us using the exchanges is risky, since many of them have closed up and ran off with peoples money. OTC trades are even more risky.
Once you have your BTC, you have to take ridiculous measures to ensure your wallet isn't somehow hacked. You can skip this step, but doing that has cost people on this forum a metric shit-ton of money..
Once you take these security measures, you can finally spend your BTC, if you so chose....but wait! what are you going to buy? The btc market mostly consist of virtual items, black/grey market items, and trinkets...and if you are lucky, the seller will value his "rep" more than your money, and actually sends you the item (or doesn't scam you with a fake item) because there is no way to chargeback.... you could go with escrow, but thats another extra step that shouldn't be needed just to by a bitcoin keychain or whatever.
Add in a poisonous community that scams each other at every given turn (just look at all the ponzis and other scams), and you can see why I dont think this will go anywhere.
I think its cumbersome nature and main userbase aren't going to be changed anytime soon, and certainly not before scammers run this shit into the ground.
Hey Evolve, you know how I used email back in 1989? I had to physically connect my telephone receiver to a device called a "modem", then dial up the number of a thing called a BBS. I then had to input a string of commands into my computer that would connect me to the BBS and start up a programme called a "client", through which I was able to "download" my emails. I would then disconnect from the BBS, write my replies, then start the whole process up again and tell my "client" to send the replies. I would do this, on average, once a day... normally in the evenings. And I thought it rocked! But at the time, most of my friends and family around the world thought it was too cumbersome.
Now they email from their iPhones and Blackberries... so again, the only failure here is a failure of the imagination.