There are quite a few unknowns as far as the DC Extended Universe is concerned - but none is bigger as to whom will be the next Hal Jordan (after the much derided Ryan Reynolds portrayal). However, we might have an idea now about the actor who will bring to life one of the most powerful Green Lanterns ever.
A couple of days ago the web started roaring - apparently, select audiences have already seen Batman v Superman: Dawn of Justice and they are already calling it a hit (despite the fact that many remain circumspect after the release of the very revealing second trailer). Among others, in filled of spoilers reviews, the word came out that the entire Justice League will be united at the end of the movie.
Thus, if the first 2 acts will be Batman v Superman, the final act will be all about the Dawn of Justice. And, as you guessed, those reviewers say that one Green Lantern will also appear in the end - none other than Hal Jordan.
So who portrays him? To everybody's surprise, it is a great unknown actor, if we may say so. In the Batman v Superman credits, the actor who portrays Hal Jordan is revealed to be Dan Amboyer (he is credited as being just a drone pilot). Rest assured if you haven't heard of him - thus far, he has appeared only in TV series, TV movies, and have provided characters with his voice in some games. Other than that"¦
Of course, this should be taken with quite a spoonful of salt. First of all, we have no clue whether or not those reviewers have actually seen the move. Secondly, and most importantly, the Green Lantern movie will be a Green Lantern Corps one - so having just Hal Jordan doesn't make sense, when multiple Earth based Lanterns will be present.