Namor's one of Marvel's first characters, debuting in 1939 if I'm not mistaken. Despite having a legacy as long lived as Captain America who debuted a few years later, Namor hasn't had a stable ongoing since the 90's, when EVERYONE had an ongoing for at least a year, it seemed (his lasted dozens of issues); and even then the title usually had to bill him as "Marvel's First Mutant Hero" or whatnot to piggyback the X-Men's bursting popularity (when any mutant was "cool"). Much like Dr. Strange, for many years afterward he retained his status through many guest appearences but struggled with his own series. And it's not just him; AQUAMAN over at DC has also struggled for years and could claim a simular fate (only Namor, at least, never had the stigma of SUPERFRIENDS, even if his appearence on SPIDER-FRIENDS was no less embarrassing; the Chamelon beats him with an pool full of alcohol basically).
However, DC has taken Black Adam and essentially reformed him into a near carbon copy of Namor, only he's on land and in the Middle East, and thus more relevent to today's times (imagine that! DC being more "relevent"; some Marvel Zombies seem to believe only Marvel can do that). What Namor has to do is leapfrog off CW enough for initial sales and hope to get a great creative team to continue onward.
IRON FIST, another once-popular B-Lister who gained some fame in CW, has an A-list creative team and debuted at #52 and likely will bleed many readers until he finds a stable audience. Hopefully Namor fares better.
You'd need a writer with some competant knowledge of political affairs beyond Extremist Liberal Bleatings (re: Millar, Jenkins, Bendis, etc) as well as a flair for imaginative settings AND able to handle making Namor arrogant, regal, but readable. On the other hand, being a all-out unlikeable jackass only made Vegeta a fair rival to Goku on DBZ/GT. Crude, but there you go. If it works...
I surely don't envy whoever takes this assignment. It'll be tough. Especially for a Marvel that from 2000 until 2006 seemed incapable of handling any non-urban franchise.