Initial thoughts - I'm underwhelmed. While it certainly has some moments where it delves into gritty, urban warfare, I'm worried it jumps around too much all over the globe. Black Hawk Down worked because it felt tight, claustrophobic. You cared about the characters not because you knew who they were (seriously, character development was a dirty word on that movie), you cared about them because of the fucked up situation they were in. And this Battle: Los Angeles has the chance to up that ante.
Let's hope it's just a bad trailer.