Please read the news article/interview I did with Kevin Hinkle.
It was all a communication issue between LEGO employees. Thankfully, there is still a future to Ninjago. If business continues to bring Ninjago to the top 5 best-selling themes, then it could very well stay around for longer.
Also, we've heard that there has been some development started for the third season of Ninjago, so chances are there will still be sets next year.
Another thing that this pertains to on the Ninjago Wiki is that if Ninjago ends, TNW will start fanon contests, which will open up more room for an expanded story.
Edited by Meiko, Jun 15 2012 - 07:11 AM.