Expanding on Bug 1074586, possibly done as an addition after the easy part.
The idea would be to add a score to the bug_interest table.
Bugs that you are involved with and have had a "change" are scored 1.0.
Bugs filed in watched component get 0.7
bugs that are related (depends/blocks) to interesting bugs have 0.5 * $x, where x is the score of the interesting bug.
This has a complexity cost, but the value is for very busy developers being able to sort bugs based on another metric. The idea could be expanded where bug_interest is related to its importance or priority.