Iwata is delegating some of the Direct presentation to Mr. Morimoto, who appears to be his protégé. Iwata thinks injecting new blood into some of the directs is a good thing.
I can't help but shake the feeling that following Iwata's health scare, he's putting plans in place in case things happen again or he has to retire for his health. Last year, no Directs happened between Iwata falling ill and him returning to work. It makes sense for him to delegate some of it.