MS can't really do anything to prevent it. Netflix are in this market to make money and bringing their own service will bring them more money and enlage their user base. I really can't see MS bulling them but I can see MS trying their hardest to prevent it by offering them bigger shares of the profits. It's just a matter of time. 

hopefully. i don't see it tomming in the near future, though. as Sony already has some sort of video service (and Netflix won't be in Canada i'm assuming :(  ) 

yes they will

Yes. 
Hopefully it'll also be on Wii :(

Hopefully, because I'm too lazy to ship my DVDs back.

I seem to remember seeing a story of how Netflix is exclusive to Xbox 360 for console. It would be nice if that were untrue, though. I believe Sony has already started integrating it into Blu-ray players and televisions.
 
EDIT: [source]
But at least there's still PlayOn.

I'm not a fan of having to put a disk in to make it work.  I'd rather buy an app off the PSN store and i'll be able to do it whenever i want to.  That's the nice part of having Netflix on the 360, it's always ready to go. 
 
Make this an app on the XMB and not a disk, and i'm all over it.  Oh, and improve the interface over the 360 version which i'm sure will happen.

it would be cool if it was. i don't really care because i'm not a netflix user. i used it on my 360 and i didn't like it to much. the quality was bad because of the internet.

I got my disc idea from the official Netflix survey they sent out as seen in this Engadget article: 
 
http://www.engadget.com/2009/10/24/netflix-hints-at-watch-instantly-integration-on-already-popular/  

ps3 already has a great movie store (overpriced rentals though). so yea the next thing is obviously streaming. i have the browser though, and i stream a ton of movies using programs like divx and it plays and sounds great. 

I think its been long rumored that the PS3 and even Wii will be getting Netflix streaming. I wouldn't doubt if there wasn't some additional fee involved as I'm sure Netflix receives some sort of compensation from MS for the service. 
 
It's a really neat concept in theory but unfortunately the average quality of content on there is pretty low. Couple that with terrible transfers (all the Starz play movies look like garbage) and you have a service that isn't quite ready for prime time.

yeah

Apparently it was the PlayStation 3 according to this blog post.

Good for Netflix.  They'll be making more money now.

No way microsoft paid good money to make sure they don't!!!

It's now on PS3 as well.  Love how Microsoft handles their "exclusive" lol...