Hmm...I've got something to say. Everyone here must know Klonoa's still famous in Japan - And game culture has been quite different in Japan. What's more, Japanese companies would made games which might only sell well in Japan before.
That's, if Namco wanted to make a new Klonoa game, they should had done it already for it was still profitable in Japan - Namco could even have another team made it.
The story of DtP was a completed one, not a nice cliffhanger could be found. Klonoa works seemed to be troubled by this problem, so they bypassed it by making spin-off games. But making too many spin-off games doesn't sound a good idea, right? Maybe they finally pushed Klonoa aside for it was too difficult to think a new and interesting story.
If my guess was right, then the petition isn't the best solution - They're still out of ideas!