Yes Nintendo discussed in a press release back in March that Netflix will be available for the Nintendo 3DS this summer, it will cost around $7.99 a month and work similarly to how the Wii handles Netflix streaming.
For more information see this article – http://www.crunchgear.com/2011/03/02/nintendo-3ds-to-get-netflix-streaming-and-free-att-wifi-by-this-summer/