I will be happy if price will not fall and we stay $330 - $380. Don't expect that will jump over $400 especially before Christmas..
It does not matter if the price will go over $400 or not in short term. The volatility of the price matters more than the value of price itself. Many countries use US dollar as a reserve currency, as the value is stable. The normal daily price fluctuation is less than 1%. The normal daily price fluctuation of bitcoin is more than 5%. So retailers will not mark the price of goods in bitcoin, but local currency.