We should standardize what we call part 2. Is it 'part two' or 'Naruto Z' or still just 'Naruto' continued.
I personally like Naruto Z, just because it makes the narutards I see go crazy. They lose it when you compare Naruto to DBZ.
Back on topic: They are definitely going to add more filler, but the problem is what. I don't see what they can possibly add anywhere other than show parts of the time jump. They might extend the Kakashi Gaiden, but that would be a huge waste. (start over and call the series 'Obito' for a while?)