Namor's a hard character to cast, largely because he looks so ridiculous and acts like such a douchebag.
I feel like you'd need somebody who looked very stereotypically half-asian, or you'd need a good makeup artist I guess.
I assume Namor falls under the same problem that Scarlet Witch and Quicksilver do - technically a mutant, technically part of the X-Universe, technically owned by Fox.
It would be great if Nova is introduced in the Next Avengers Movie.
A new X-Men Movie dealing with Apocalypse would be welcomed. Hell I wouldn't mind seeing the Celestials in the big screen even if its for a short moment.
Or Another Movie on Constantine.
But if they want to make something from scratch. A Film based on the Eternals. Oh Phuck Yean.
The Authority or Stormwatch should get a movie. I think it would be decent because of how mature the movie would have to be. I enjoyed the Watchmen, and think that if either of those teams got a shot at a movie that it would be, or should be similar to the Watchmen. Heroes dying, or getting severely hurt is what may be lacking in many of these Super hero flicks.
Powerman and Iron Fist in the old days of Times Square set it in the 70's or early 80's it would be great! The origin stories alone would be an awesome 30 minutes.