Correct me if I'm wrong, but I gather that you need to load the netflix disc every time you want to stream stream something?
On my 360 (and I assume on PS3s as well), netflix streaming is built into the software of the device: I can play a game off of a disc until my wife gets home, then switch over to netflix and watch some tv with a few button clicks.
If you have to get up and fumble with discs every time you want to switch tasks, this is a big Fail for the Wii in terms of convenience. Why not a WiiWare application?
PS3 streaming also requires a disc. I heard it has something to do with xbox 360 exclusivity agreements, but I could be wrong.
For God's sake, stop researching for a while and begin to think!