From what I've read the film is along similar lines to Jesus of Montreal (1989) and Man Dancin' (2003), although it is about the making of a Jesus film rather than a Passion Play as in those films. This would make it similar to Pasolini's La Ricotta (his contribution to four-films-in-one film - Ro.Go.Pa.G.), which I've never seen, but Peter Chattaway discussed at his FilmChat blog a while back.
The cast is an unusual mix combining queen of european cinema Juliette Binoche with Heather Graham (of Boogie Nights and Austin Powers 2 fame) Matthew Modine and the much underated Forrest Whittaker. Modine (right) plays Jesus in the film, looking like he's just stepped off one of Holman Hunt's paintings. For what it's worth this shot is very reminiscient of the first view of Jesus we get in Roger Young's 1999 Jesus film. There are more shots from the film up at the official italian website, and some of them look incredible. Also, a number of clips from the film and the trailer are now online at Twitch.
Despite general release being a way off, there are plenty of reviews up already. I personally don't want to find out too much about the film before I see it, so I've read the Variety Review and little else. If you don't want to wade through a large number of reviews then it doesn't seem to give away anything that wuill spoil the film, pluis it's a respectable enough publication to be fairly reliable. There are more comprehensive lists of reviews posted at both Rotten Tomatoes and the IMDB as well as a number of user comments at the latter.
So although I'm not sure when I'll get to see this (perhaps even not until the DVD release), I'm very much looking forward to it. I recently got hold of Ferrera's most famous film Bad Lieutenant, another film I haven't seen, but I'm led to believe it also touched on religious issues. I may post some thoughts on that once I have seen it.