Here's some evidence:
1. The Chinese are starting to buy a bunch of it and the government practically endorses it.
2. The closure of silk road only temporarily depressed the price (although if/when the fbi sells the seized coins the price will certainly drop for a while, but it will be good to get bitcoin into the hands of honest people)
3. The first bitcoin atm's are opening up (in Canada) and it is becoming easier for businesses to accept the coin.
Plus, I think if bitcoin becomes large enough most stores will want to follow the rules and tax bit coin transactions. This would slow any negative potential government intervention. Once you can buy all of your groceries at Walmart with bitcoin I can see the market cap approaching $1 trillion (in several years).
If the current trend of bitcoin price continues (~1000% year) it could easily hit $1,000 next year, at which point it will be hard for me not to sell some
Why whould u sell if u can buy food and go to cafge with BTC ?!