I am pretty notorious for not updating my addons often enough (I think some of the versions I have must be years old by now), but maybe with this, I'll be better: Reader Fin runs a website that tracks RSS updates of addons from most of the database sites, so all you need to do is hook that feed up to your reader of choice, and then whenever a new addon drops (either one that you're waiting for, or all of them, if you just want to watch them go by), you'll see it pop up in your reader, ready for inspection or a download or whatever you like.
He's also hooked it right up to a Twitter feed, so you can also tune in on Twitter and watch the new addons go past. I thought there might be too many going out, and that all those addons might spam up your Twitter feed, but actually if you've got a full slate of follows already (I've got about 200 talkative folks), it's not bad at all -- enough to keep you interested, but not so many that you feel flooded.
Of course, this probably still won't help me get my addons updated -- only putting an extra hour or two of free time in the day will help me accomplish that one. But it'll nice, at least, to know they're out there.