I'll admit it-- I'm a lazy addon user. Whenever Blizzard updates the client, I always manage to forget about my addons. I'll log in, realize I have no addons working, and then jump back out and just "enable out-of-date addons." Eventually, those addons will show bugs, so I'll log back out, disable them, and then keep playing without them for a while.
And sooner or later, as happened this past weekend, someone will point out that I'm not running KTM, or that I don't have the latest version of CTRaid up and running, so I'll write down a list of everything I need, go and download them all at once, and refresh them all completely. When I do this, it's a good feeling. It makes the game seem new again to me-- everything works, and everything does what I want it to once again.
Until Blizzard puts out a patch, and then the whole grueling process starts over. I would just download new addons when a new patch drops, but addon authors aren't all on the same schedules. And I know programs like the WowAceUpdater help (by checking for updates for me), but so far I've never gotten around to installing those programs either.
But that's just me, and I've got to deal with my own problems. How often do you refresh your addons completely? Do you have a good system for keeping your addons up to date, or, like me, do you only get around to redownloading everything when something stops working?