Pretty short and sweet; Netflix's streaming video service is coming to 3DS, but it's only been described as coming in the summer.
I personally love Netflix's streaming service, and have a subscription that I don't have any plans of discontinuing. I don't see myself opting to use Netflix on a 3DS over using something I can watch through a television when I'm at home, but it's neat to have this free portable option. It doesn't have the versatility of an iPhone since it's locked to Wi-Fi, but 3G Netflix isn't so hot as it is.
There isn't currently any 3D content on Netflix, but if they add it, 3DS has a pretty good chance of getting it. Theoretically, it would need to stream twice as much data, but if the 3DS has a good bandwidth on it's Wi-Fi chip, then it shouldn't be a problem for the 3DS at its resolution.