I seriously cant imagine the possibility of these studio's admitting that they made a mistake with the first 'Hulk' installment, and deciding on a definate remake of that same movie. Keep in mind though, that remake implies that key elements are kept the same, but perhaps dramatised differently. A remake wouldn't actually get rid of any character, so if this movie was indeed a remake in the regular sense of the word you'd still have Bruce's father, in the flesh. There's a difference between remake and reboot, and I think people are getting somewhat confused about the two. 'Batman Begins' was reboot of the ailing Batman franchise, disregarding the original movie's ('BATMAN) telling of the origin and bringing together an entirely different version of the history for Batman ('Chill' kills the Waynes, like in the comics, not a young 'Jack Naiper'), but both are origin stories, which this new Hulk movie isn't.
I firmly beleive that this new Hulk movie will be an 'unofficail sequel' in every meaning of the word. Meaning, that while the movie will continue on from Ang Lee's 'Hulk', you'd be none the wiser for knowing so whether you had seen the preceeding movie or not. It will be different in tone, probaly cast different to some degree or another, and wont carry on or develop any seeds of plot elements from 'Hulk', but will stand alone as it's own movie.