I know that you can import your own videos, it doesnt have to be from itunes. BUT, if you cant watch it on itunes(its basically like windows media player, you can import stuff , but if you cant see it cause of incompatibilities, than u cant see it) its the same in itunes, but with the new Apple TV, you will probably see an expansion in compatabilities with different video types. In itunes I have importted my own video, so i guess yeah.
I heard all this in KFI PODCAST by Leo Laporte. He did mention the netgear you mentioned but that it might not be super easy. You will probably have to use a specia player with the netgear as well.
Anyway, in my opinion the APPLE one should be good , because Apple, according to many people" is known for great user interference" I would again reccomend the Apple one. If it doesnt work for you, there is always the return period.
U should try b4 you buy.
Does the netgear support 1080x? x= i , p.
Now that I looked at the netgear one, it does seem pretty good. Although its not out yet. So both the one you posted and the apple one are not out yet so you will have to wait . Try whichever one you feel the best vibe about. If it works with you, than keep it.