With a few good suggestions, I had a reasonable solution but it still required a bit of manual markup to prepare the example. Then I saw Pranav Prakash's post about syntaxhighlighter by Alex Gorbatchev.
With a few tweaks (see the stackoverflow question for the details), I'm now able to combine the best of both worlds: great formatting and syntax highlighting with syntaxhighlighter and also line continuation glyphs. Here's an example of the result:
public class HelloWorld {
public static void main (String[] args)
{
System.out.println("Hello World! But that's not all I have to say. This line is going to go on for a very long time and I'd like to see it wrapped in the display. Note that the line styling clearly indicates a continuation.");
}
}
NB: if you have javascript disabled, or reading this through a newsfeed (or if I hit a bug) you may not see the full effect. Here's a screenshot of what should be appearing above:
Now I just need to go back and update the code formatting in all my old posts. Basket!