I think most anime/manga have the potential to be translated well to live action. I think the only exceptions being over the top shonen titles such as Naruto and Dragonball.
Many titles have already been translated well (albeit with some modifications) such as GTO, Gokusen, Touch and Nana. Any it looks like the A****a no Joe movie is turning out OK.
http://www.a****ano-joe.com/trailer/
Of course none of the previous mentioned manga adaptions are very special effect heavy productions and are more dramas that are story driven. The real question is whether the Sci-Fi/Fantasy mangas can be adapted well to the big or small screen.
As far as Japan goes, their special effects have always been behind the big hollywood studios and it shows in many of their movies.
Taking a look at the upcoming and highly hyped Space Battleship Yamato you can see how obvious that gap is
http://www.youtube.com/watch?v=6fQoh6AIgNE
The CG for Ryuk in the Death Note movies, although good, was still quite noticeable.
There are many manga I would like to see in live action like Hajime no Ippo, Ruroni Kenshin and Berserk. HnI and Kenshin would probably be doable (although kenshin may need some toning down of some of its Shonen qualities). Berserk would need quite the budget to be made considering the need for CG for the apostles and set pieces. I would imagine a 300 type approach in film making would be the best avenue to adapt Berserk, but it would take someone dedicated to stick with the large amount of source material over time.