Some WebKit Nightly builds are a lot more stable than others. I was wondering if there was any way to automatically pull builds for which you receive a lot of crash reports, to spare people from updating to builds with major problems you already know about. Maybe there could even be a way in the application to leave feedback (maybe a thumbs-up/thumbs-down)? I obviously don't have any idea how your reporting/autobuild system works, so I don't know how difficult this would be.
When a nightly build is bad enough to be nearly unusable, we fix the problem and make a new build. This doesn't happen very often, and doesn't take too long to resolve, according to my observations. It's still good to have such builds archived to find out when other problems started. CC'ing Mark Rowe, whose opinion would be more authoritative, but I expect him to agree.