How many iPhones, iPod touches, and iPads were opened on Christmas? Check out the Facebook for iPhone download spike above for one datapoint. A second datapoint comes from Tap Tap Revenge 4:
Tapulous tells us that peak Christmas downloads reached 45,000 per hour, and that holiday download traffic is twice the levels of last year.
Facebook is probably the most popular iPhone app of all time and TTR4 is among the most popular right now, but the mapping is probably still not be one-to-one. Either way, that's a lot of iOS devices under the tree this year.