The only real long thing will be that skidmark in your undies from your bowels contracting in fear from your short position.
Although I have yet to determine the impact of G+ on FB (not enough data), for now, everywhere you look, even on TV, there is the FB icon. It is ubiquitous. Businesses, clubs, groups, high schools, and all manner of social groups are on FB.
For how long I do not know. These things are fickle, and most people use it because it is free.
The best plan is to trade price and trends. Not enough time has passed to say FB is a long-term investment.
If long, use stops hard or mental. Same as short.
Personally, I do not see FB ever really taking off until all these insiders, especially Cheryl "Sell Sell Sell" Sandberg, have finished selling. It is near criminal the amount of shares these people were allowed, and a 2-billion dollar float? That is outrageous.