I haven't gotten around to watching the whole Comic Con presentation, but early on, Bill Prady says that they can't legally broadcast the first episode and although they screened it at Comic Con claimed that they couldn't even legally show it there (though they did), claiming that the Comic Con audience was the only people who would ever see it.
I hope he was joking. I kind of feel like he was, considering the pilot was available for screening in select cities. I was really hoping that it would become a bonus feature on the season one DVD. I had wondered whether the plot would be expanded and they'd incorporate footage from the pilot (if they did, I guess they'd reshoot the scenes with Denise since she's getting rebuilt).
After all, clips from the pilot have been used in the trailer, which has not just been shown online but in TV commercials. Wouldn't they expect casual fans to see the clips in commercials and wonder why they aren't seeing them on the actual show (or maybe they expect people to search online if the pilot is leaked)?