Possibly. The Joker had no plans, but if you really think about it, he kind of did. Y'see, The Joker was kind of a contradiction. That was evident when he spewed two different stories about his past.
Well, that was just more evidence that Nolan is an actual Batman (comics) fan.
The Joker's never told the same version of his origin twice. And that includes times that he's not TALKING to anyone, but rememberig things by himself. It's pretty well established in the comics that most of what he knows about himself is essentially hallucinatory self-delusion...
My personal favorite version of his origin (and thus the one I tend to accept as being closest to the truth) is the one Alan Moore wrote for "The Killing Joke." This is the one that Burton sort of "borrowed" (but not completely) when he did his own "Batman" movie.
He was an enigma, a mystery, perhaps even to himself. He did everything he did in The Dark Knight to manipulate the world around him and it didn't matter what he did or how he did it. He definitely had plans, despite whatever he spewed to Dent or Batman.
The only "plans" the joker has... that he's EVER had... has been to "let everyone in on the joke." The "joke" of course, is the total insanity, harshness, etc, of existence in an unfeeling, sadistic universe... (as he sees it). And he's anxious to win converts to his own personal worldview... what he believes to be the only real TRUTH in existence!