Nintendo is pretty bent on staying a game company. They may make attempts at cell phone connectivity, but at the end of the day, people will still be buying their systems for their games.
Besides this, I still haven't seen any solid evidence that smartphones are lessening current DS sales. It's still selling very well as a game system. Sales have been down YOY, but that's more of an effect of the 3DS coming and also the DS reaching high saturation.
Another thing to keep in mind is that Nintendo is very much against any kind of monthly fee on their customers. Last year Iwata said at a stockholder meeting that they would only include 3G if they could find a way not to have a monthly fee (taking the example of Kindle where the connection is paid through sales). Seeing as the 3DS does not have 3G support, it seems as if they couldn't find a way to do this.
As for 3d Movies, I imagine that this will be some kind of pairing with Netflix. Since their instant streaming movies were moderately successful on the Wii, they will likely bring Netflix to the 3DS and have 3D movies exclusive to the system.
The one hope I have is that pictochat will actually be useful now that you can send messages without other DS systems having to be in a chat room. If I could go to the mall and see everyone within the radius that has a DS, it would be interesting to send off messages to them. Where a cell phone is a good way to stay in contact with friends, the 3DS may be a better way to meet new friends.
