While I was busy not doing anything better, I found myself wondering how far (if at all) District 9 took the Christ allegory. As I mentioned in my little review of the film, District 9 does stick pretty closely to the Monomyth pattern with regards to the main character Wikus, and where would you find a more famous application of the Monomyth than the story of Jesus of Nazareth?
At this point I came to an interesting realization: Wikus isn't an allegory for Christ... The alien Christopher Johnson is.
Let's start with the most obvious point: his name. Christopher Johnson's initials backwards form JC. Okay, so maybe that's a bit of a stretch, but bear with me. Further, the name Christopher (a rather unusual name for an insect-like alien, don't you think?) is of Greek origin and literally means "bearing Christ inside." Another allegory could be the connection to saint Christopher, the patron saint of travelers who, according to legend, carried a small child across a great river. Recall in the film Christopher, having confiscated the mothership, taking his young son across the galaxy to their home planet.
Now, let's look at a few parallels between the lives of Christopher Johnson and Jesus. Christopher is descended from a race who are being persecuted; he is on a quest to save his people; while on this quest, he is betrayed by someone he trusts (Wikus, who knocks him out and steals his shuttle); and finally, he "ascends to Heaven" with the promise of his return, and with it the salvation of his people.
Maybe I'm reading a bit too much into it, but I think it's an interesting perspective.