I think the biggest problem right now is.. where do you buy Bitcoins? Seriously, where does the average person buy bitcoins right now? The exchanges? No way!
Why not? (honest question).
I honestly couldn't imagine anyone in my family wiring USD to mtgox (from a GBP bank account), going thru the process of trading then pulling the bitcoins back to the client (which no one in my family really understands)
Now, if there was a website where you could buy bitcoins into an online account with a credit card in a few minutes, then have them (almost) instantly usable with a barcode enabled smartphone app, that would be different.
Same here. I talk to people about it and then they say "That sounds great! How do I get some?" ... "Urmm well.. I can buy some for you via #bitcoin-otc and then just transfer the balance to my bank account"... "...oh.".
Maybe it's just a GBP thing.
The encouraging thing is the... "that sounds great!" part.