The news of added shares to the Facebook IPO (additional 85 million) is diluting the trade. The interest and projections of the demand for shares seems to reflect a move to seize some of that premium now by making more available.
The valuation is setting itself up for vulnerability unless Facebook operates at a high level post IPO. The first question will be the ability to maintain the trading level out of the gate ($34-$38).
I believe in Facebook long term but the slim margin of error for EPS expectations now escalates the idea that Put protection might not be a bad idea. The market cap projections (now over $100 billion at the high end) are definitely pricing in impeccable expectations from operations (especially mobile).
Day One as a public company Facebook will be straddled with the concept of going forward with no disappointments allowed during their rookie season. And perhaps a tighter straddle is how options are best played with the intent to cover less range between the high and low. The more profits that are extracted (now) by expanding the float will affect the public trade based on a moving EPS target.
Disclosure: I have no positions in any stocks mentioned, but may initiate a long position in FB over the next 72 hours.