The best posters IMO have been the ones where you can actually make out the details (Catwoman one for example)... not the ones IMO where everything has been garbled together in a low-resolution, photoshopped mess. This poster suffers from that. The burning city can barerly be made out, and the Batman still is very cut and paste.
Like I said though, I do like it conceptually... it just leaves so much to be desired. Imagine how awesome that could look if they actually bothered to try rendering it all from scratch.