Bob's suggestion is a very good one in my opinion. If there were display of the number of "merges waiting on me" on our Nav Home Page, viewable for our own eyes, not as a public display, it might nudge more users to work on their pending merges. As a public display, I'm not so sure, since that could be construed as public humiliation :) A to-do list is more prominent when it's "on the fridge door." And wouldn't hurt if it went out with the activity feed, either.