The scary thing is that anything is possible at this point. The announcement of the IRS taxing Bitcoin has already caused it to fall 11% in the past 24 hours, one of the biggest drops since the Mt. Gox incident. If something similar were to happen again now, I could certainly see it going under $300.
However that's quite unlikely. A lot of people have buy orders in the $400 range, including myself. I think Bitcoin will slowly recover and continue to rise. I certainly wouldn't be selling right now.
My vote goes for $800.
Long term the price will rise and there is a lot of support each time we go down a tiny bit
A huge problem in the protocol or something similar is always possible but it is probably priced in and unlikely
A huge problem in the protocol is definitely not priced in.