About the casting, I've heard in interviews that they've been talking with Viggo Mortensen and Ron Perlman. Nothing's confirmed but Jackson showed interest on working with Viggo again and Del Toro has been working with Ron for ages.
I'll wait to see the movie, before I judge who I'd want as a director. I liked PJ's work on LotR, but at the same time I'm open to del Toro. Its more about the story anyway, and what JRRT had in mind.
Really the only thing that I really want is for James McAvoy to be Bilbo. I'll definitely be disappointed if its not him