It seems like it should pop but if you look at recent additions. Look at TXN on 4/23/2012 VIAB 5/30/2012 MDLZ 7/23/2012 on their inclusion into the Nasdaq 100. What they all had in common was a pop in volume the trading day before the inclusion and there was not much price change. The day of the inclusion saw less volume and had no price change. Check this out on a historical price setting and look at volume and price.
The Fund managers don't just buy at one time. They strategically buy and they knew of Facebook's inclusion prior to the ipo. The number of shares is not much as many people think.
This is why there was not a pop today. This isn't to say there wont be a rise tomorrow but how much can we expect? A rise to 30 is quite a bit based on how the Nasdaq 100 inclusion has affected other stocks like those aforementioned.