James Robinson's first issue of Justice League of America is a lot better than the issues of Justice League: Cry For Justice that have come out so far, but it also gets hurt a lot by some general editorial issues.
1. Robinson is taking over from Dwayne McDuffie, who was recently forced by editorial decisions to do a big ol' thing where Vixen and the various heroes left over for McDuffie to use made this big deal about how THEY were dedicated to being in the Justice League (sort of like Aquaman's formation of JLDetroit years ago).
Well, while editorial decisions put McDuffie in a situation where he had to come up with convoluted reasons why characters were leaving the book, he at least turned it into a "This is why these characters WON'T leave."
Of course, now Robinson is writing the book and he doesn't want to use any of these characters, so now, only a few issues after we got "WE'LL never leave" we get "Okay, we'll leave" and some of them are pretty iffy (Doctor Light, for instance, does a complete 180 from a few issues ago).
2. Robinson's run on Justice League takes over from his mini-series, Justice League: Cry For Justice, specifically the conclusion of that series. Which is fine, except, you know, Cry For Justice hasn't finished yet! So we're discussing the conclusion of that series while it hasn't actually happened!
3. His first issue leads directly into a crossover with Blackest Night for his second issue.
That's a lot for a writer to overcome, ya know?
Luckily, Robinson acquits himself pretty well - he tells an engaging story with a lot of strong action (Mark Bagley is particularly good on the art for the book). If it weren't for those obstacles which are mostly outside of his control, I think this would be a comic I might even recommend, which is a big improvement over Justice League: Cry For Justice.