I don't think it's a bubble, there are still too many people who have never heard about btc.
I'm sure hundreds of millions have heard about it. There's an enormous gulf between hearing about it and figuring out what it actually means though.
And up until now, in virtually every print article or online news article, they've been reminded of nothing but the bad news surrounding Bitcoin (e.g., Mt Gox implosion, China "ban", Charlie Shrem arrest, Silk Road, etc.). So they know of it or have heard of it, but the articles put a "stay far away" negative spin around it. Almost a condescending tone, as if to say 'you'd be a silly fool to buy some bitcoin based on all of this bad news.'
But imagine what will happen after the next cycle or so, when the press starts reversing previous bad news surrounding Bitcoin, and actually starts putting a positive spin on it instead? Like quoting the PayPal CEO, or when PayPal/Amazon/Facebook/Apple adopts it, or a big name financial institution endorses it, ETF fund, etc.
I mean look at this news, and yet hardly anyone in the U.S. even knows about this:
http://finance.yahoo.com/news/reeds-jewelers-now-accepting-bitcoin-120000388.html
http://www.reeds.com/about/Bitcoin.html
I can hear the articles of the future now, "...previously we were skeptical of Bitcoin, but with recent endorsements from X/Y/Z, we are suggesting that everyone should purchase and use some bitcoin." When that happens, then public perception will change very rapidly.
This sea-change happened with the public perception of the Internet, I should know as I'm old enough to remember the evolution.