Hi Rob, that's a cool idea.
+1 but I would use the word complexity instead of difficulty.Usually the issue tracker database is customer driven (severity) but a helper field to sort bugs by complexity will help developers to focus on more complex issues.
If there are no objections, I'll add a new field to Bugzilla called "cf_difficulty_level", and which a drop down UI with the following choices: UNKNOWN (default) TRIVIAL EASY MODERATE HARD WIZARD
Kind regards, Joost
