I think Director Pete Docter who helmed the development of UP describes quite well what the movie is about:
"We wanted more ‘Dumbo’ and less ‘Star Wars,’. In certain parts, it’s more of a feeling we’re going after than linear storytelling."
Director Pete Docter
I understand Pixar may be tempted to explore Miyazaki's path (the Japanese director who brought some really magic animated movies) but I'd rather see Pixar staying a trendsetter than becoming a follower...
Anyway, Disney Pixar's UP still looks amazing.