I just did a quick test with UIScreen's +screens method, to see if the TV Out would also be seen as a UIScreen. Unfortunately, +screens returns only one screen (that of the iPhone itself). So how to display stuff on the TV-Out?
Thanks. M
Yes. This is possible. Make sure you have another screen connected (i.e. that you have the video cable connected through a universal dock).
Also, if you are interested in mirroring the display, see: http://www.expertisemobile.com/2010/06/24/presenting-your-apps-on-the-big-screen-screen-mirroring-for-ios/