I would have thought the console was nearing the end of its life, game wise. But according to Nintendo's CEO... no, not really. They've apparently got quite a few major titles left to announce:
Honestly, what else is there for them to do console wise? Unless somehow they come out with a 4DS, we wouldn't be able to comprehend it, there isn't really much left in the handheld department. So why not just stick with it and keep making new content. They can always update the system with better hardware like they did with the XL and continue to make a profit. It would actually be better on the users so they wouldn't "have to" buy a new console every time one gets released.
Personally, I think they should just stick with what they got and make improvements to it as they go.