Ok, my Wordpress bashing might be a little knee-jerk, but they did just have to force-reset all wordpress.org users' passwords this week.
Anyway, it appears that Dropbox is becoming the latest service that I'd be hesitant to use for even casual purposes after they just hosed their own authentication system for four hours earlier this week. This might even be worse than the Wordpress stumble, since they can't even blame a malicious, outside entity. Dropbox's latest problems, combined with their questionable deduplication practices that have raised security and privacy concerns, make me glad that I've never signed up for an account. And don't get me started on their attempt to bully an open source project with a DMCA Takedown notice.