Ok, a few thoughts.
1.) It could be entertaining IF they can find the right balance between action and comedy. Frankly, I felt Pineapple express did NOT find that balance and was merely mediocre as a result. Interesting concept, poor execution hampered by too much self-deprecating stoner humor. Not that I don't like that, but I don't like it mixed with action. Other "genre mashups" have been problematic, too. Club Dread, for example. Is it a horror movie? Is it a comedy? It couldn't decide, and suffered as a result. Not funny enough, nor horrific enough. That's gonna be the biggest issue with this film.
2.) I remember when this character was called The Pink Panther. He had a sidekick named Kato, too, who did all the heavy lifting.
3.) My understanding is that (setting aside the 1960s cheese-ball show, which, you may recall, ran alongside the 1960s cheese-ball Batman show), the Green Hornet is NOT a comedic character, and that while Kato can certainly kick ass, it's not as if Kato does all the heavy lifting. I can understand wanting to downplay the "Ah, my trusty minority manservant" angle, but you don't have to flip the roles or downplay one's competency in order to do that.
4.) Seth Rogen isn't really all that funny to me most of the time. He seems like a fun dude to hang out with, but I don't find his films to be all that funny.
