Just like with every bubble, some people will wait and wait again to invest in... Only once all their friends will have gain some money speculating, once the main media will say it's an easy way to make money, when they'll have the feeling that eveybody else is making money, only then will they invest in... And loose everything the next day, after the bubble collapse.

So, if you're planning on speculating with bitcoins, do it right now, or never do it... The chances are it's already too late btw, since people are already mentionning exponential growth.