Title text: I'm really worried Christopher Nolan will kill a man dressed like a bat in his next movie. (The man will be dressed like a bat, I mean. Christopher Nolan won't be, probably.
This comic is a reference to the comic book and movie character Batman, who is actually wealthy playboy Bruce Wayne, as we see on the left being referenced as "Master Wayne" by his butler Alfred. Batman, in contrast to Superman and other comic book heroes, has no superpowers — he's just an ordinary guy in a bat costume, or "a man dressed like a bat." Despite the accuracy of this description, it sounds pretty stupid if you take a serious line and "Batman" with "a man dressed like a bat."
In the middle is the stick figure representation of Batman and on the right is the Joker, as played by the late Heath Ledger. Each of these is an actual scene from a Batman film, with the subject text replaced. In this way, Randall is pointing out that he Batman commands a lot of respect and fear considering that all he is is a man in a costume.
The in title text, Randall expressess his fear that Christopher Nolan (the director/producer/writer of the latest Batman trilogy) will kill Batman off in the next movie (Dark Knight Rises). Of course, Randall substitutes for "Batman" as in the comic. This causes a grammatical ambiguity which Randall points out where the "dressed like a bat" could apply to the "man" or to Nolan. A similar ambiguity explicitly discussed in the title text of 1087: Cirith Ungol.
- [One panel, depicting three wavy circles. The one in the center is slightly larger, and the ones on either side are higher up. Their edges are touching.]
- [The left circle has Bruce Wayne in the foreground, with Alfred in the background.]
- Alfred: Know your limits, Master Wayne.
- Bruce: A man dressed like a bat has no limits.
- [The center circle has a close-up on Batman in his cowl.]
- Someone off-screen: What the hell are you?
- Batman: I'm a man dressed like a bat.
- [In the right circle is The Joker.]
- Off-screen: What do you propose?
- Joker: It"s simple - we kill a man dressed like a bat.
- My Hobby: Whenever anyone says "Batman," I mentally replace it with "a man dressed like a bat."
- For more discussion see the explainxkcd.com blog comments.