I have been able to verify that on an iPhone 4 that the Netflix does not natively support TV out with the Dexim AV Dock, and I assume this would apply if I was using the Aplle AV Cables.
All of that said, if you JB your iPhone you can use the app TVOutTuner for iOS4 you can output in SD to your TV. Not great quality, but pass-able in a pinch.
So far I assume the only native (non-JB app) that works with Dexim or Apple AV cables is the built-in iPod app. Is this a correct assumption? Are there any other 3rd party apps that support TV Out at quality better than SD?
I would like to see NetFlix support native TV output.