Overall: I may watch some cartoons on it, but the Wii will not replace my hook-up-laptop-to-TV approach to watching movies on Netflix anytime in the near future. Overall the picture quality is disappointing at best and disconcerting at worst. The interface is ok. Sound is barely ok.
Interface & setup: Setting the whole thing up was a breeze. My Wii was already hooked up to my TV and sound system, so I just had to pop the disk in and wait for it to come back with a special code. I headed over to netflix.com/Wii on my laptop and entered this code (you have to be logged into your Netflix account to be able to do this, so better on the laptop than on the Wii browser). Within a few seconds the screen on my Wii changed to show me titles from my "Instant Watch" queue.
Interface: The interface was pretty typical and usable. You can browse all of your queues, in addition to a number of custom queues based on your watching habits. Each queue is a horizontal row of DVD covers. Unfortunately, this is not cached, so every time you come back from a movie, you see a row of blanks while the images are fetched. Clicking on a movie takes you to a information page. There you can "Resume", "Play from beginning" or "Remove from Queue", while reading the blurb. For TV shows you can continue watching from the episode you left off on, or browse through all the episodes. You can also rate the movies. No way to read reviews yet though.
Video: This was a major disappointment. I watched to scenes from two movies - the initial scene from the Shawshank Redemption (regular aspect ratio) and a few action scenes from the Full Metal Jacket (widescreen). The movie started about as quickly as it did on my laptop, but suffered from severe lack of color-depth and frame-rate. Watching the initial scenes of the SR with the fluid camera work was dizzying. Edges were choppy and the blacks were atrocious. FMJ was a almost as bad. Fire and smoke looked remarkably good in some of the action scenes, but again, when it came to edges and people, it just wasn't fun watching them. And if you have anything bigger than my 32" TV, you should pop in a motion sickness pill before, say, you watch Harry Potter on his broom.
Audio: Was barely alright, maybe the same as from the 3.5mm jack on my laptop. No 5.1 or any surround sound yet - good ol' stereo. But overall, the volume was a bit low, and I had to turn the amplifier up a bit. Beware though, when you switch out of the Netflix channel onto the Wii home menu - the ping will be annoyingly loud. On the positive side though, was the fact that there was no choppiness, or lag even when a movie was paused and played at random points.
Movie Controls: When you wave the Wii controller during a movie, you see the pause/play button, the time bar and a back button. A slider on the time bar can be moved to any point in the movie. You do get a quick preview of where you are, with screen shots, so you don't have to guess at where you want to end up. Overall, the controls mimicked the controls of the standard player pretty well.
Final Thoughts: The last problem with the Wii is the fact that it does not use a Infrared controller. Presently I have a IR remote to run everything else in the A/V setup. Watching movies on the Wii means keeping around one more item on the table, which you can *never* replace with a remote.