Keep in mind that F4V is the Flash-specific wrapper for H.264, along with proper metadata for playback with or without a streaming server. An H.264 video in an MP4 container with Flash-specific metadata will also work, and can serve as the fallback media for users who don't have Flash (iPad/iPhone, etc.), or have it disabled. That is, the one file will work with Flash, Quicktime, VLC player, HTML5 on Safari and Chrome, and so on.
You can use SWFObject plus some additional custom JavaScript to steer users to the proper file type. (Use NoScript for those with JS turned off, and just provide a link to the MP4 file.)
With three million iPads sold in three months, fallback to HTML5 is becoming a good idea. There are plenty of blogs and Websites that provide the page coding you can use, and if you do it starting out, you don't have to go back and change out pages later on down the road.
My
worth, and also echoing munki's excellent comments.