Not necessarily. They're not developing the new Castlevania in house. I'm sure if someone at Hudson came up with an interesting concept, Konami would back them. Of course, that's assuming someone at Hudson is even that creative which is silly.
Mario Party DS came out Nov. 2007. Nintendo will release another Mario Party game. Why? Well, why not? People are suckers for those games despite how trite they've become. It sells so Nintendo will sell it.