If you copy the movie into a folder called DCIM on the SD card it will then show up as the previous poster correctly stated.
However, you cannot play the movie from the SD card, the only option you get is to delete it or to import it to your iPad, which sort of defeats the object if the idea is to save memory on the iPad. At least thats what happend when I tried it.
I put a small movie onto the SD card, copied it into a folder called DCIM on the card, and I could see it on the iPad under camera section, but could'nt see any way to play it without importing it to the iPad first... I'd love to be proven wrong here... but it appears you can only import files from the SD card to the iPad, not play them directly from the SD card...doh :-( 'Everything has to be imported to your iPad before you can play it' I know..pathetic isn't it.
So basically, you could put several movies on a SD card in the DCIM directory, and you can play them but only after it's been imported to your iPad, I suppose you could import 1 movie.. watch it, and then delete it then import the next movie when your ready to watch it, I cannot see any other way round it.. There is NO way to play directly from the card. :-( IMO this severly limits the usefulness of the camera kit.
Love to hear otherwise.... anyone?