Are you asking if there will be a facelift compared to FO3 or the originals?
Either way, with the proposed budget (75 million) V13 will be a triple A title, complete with bells and whistles and shiny 3d brahmin I'm sure!
As far as perspective goes, nothings announced yet. I'm hoping it will be top-down / isometric but with a 3d engine. With Diablo 3's guaranteed success hopefully the industry will realize that such perspectives aren't a relic of old technology and actually work better than 1st/3rd person over the shoulder for some styles of games.