I had pretty much lost hope for this movie around the time they announced Ryan Reynolds as Hal. I don't mean to sound rude but I sort of can't stand Ryan Reynolds. Partly because he reminds me Dane Cook (who I loathe) if he took a fucking shower, and partly because I haven't ever really liked any character he has played. I always thought Nathan Fillion would have been a perfect Hal Jordan, and saw no reason he wasn't considered for the part. The trailer just served to confirm all my fears about the movie and add in some new ones. Seriously, I can't for the life of me think of why they chose Hector goddamn Hammond for the villain. He is about as lame as GL villains get, and doesn't really help set up the real villain, Sinestro. Also, hearing him say "The one thing Green Lanterns are is fearless, and that's not me" made me sad inside. They're turning Hal Jordan who is about as fearless and strong-willed of a character as has ever existed into a blubbering pussy, and that's just not okay. DC needs to get their shit together with every franchise besides Batman and start making some good movies for a change. They have the capability to put out a much better product (if you've seen the animated movies of late, you understand how excellent they are) but sit there and fester in what was cool rather than making what will be cool.
tl;dr : The movie sucks and DC sucks for making it.