I can't say I feel good about my backups. I believe data wants to die; it wants to be free of the burden of order. Against the despair of data, even the best backup is barely adequate.
Consider tonight, when everything almost failed - Time Capsule and Carbon Copy Cloner alike.
The Time Capsule serves all the machines in our home over a wireless network. I was surprised at first that backup would work over wireless, but it does. Each machine has its own unencrypted disk image; one on the TC's old internal 500 GB drive, two others have images on an external 2TB drive. The TC sits in a closet upstairs; it's unlikely to be stolen but fire would destroy it. I have done 1-2 file Time Machine restores from that image, so I know it can work. The only test of a backup, of course, is a restore.
I trust Carbon Copy Cloner  more. Each day it clones my server, on which all the important data lives. It's more than a cloner; CCC keeps copies of changed or deleted files in "_CCC Archives". I've configured CCC to use an encrypted image it automatically mounts every night. Since that backup is encrypted I can take it offsite, which I do every few weeks. Ok, every month or two. Offsite rotation relies on me, so it's prone to failure. Still, even if the house burns, I am unlikely to lose more than a month of images and videos. I can live with that.
So I have two backup methods, both fully automated, both relatively independent . If each is 95% reliable each day, then the chance both fail on a given day is 1/400. If the daily chance of a server drive failure is 1/1000, the odds of all three failing on the same day are about 1/400,000 , 
Tonight though, my data got within a few miles of the cliff it wants to meet.
My server has been having worrisome memory exception (EXC_BAD_ACCESS) crashes, and a TV show I recently downloaded had a file error . There's something wrong on my 2yo i5 iMac; I need to run Apple Hardware Test (again). So I know my server data is at risk.
Time Capsule has had problems too -- it's reporting a "communications error" periodically. I think that error message is a scarlet herring related to the iMac issues, but clearly I can't trust that backup.
Happily there's good old CCC -- but when I restarted my server for the first time in weeks it reported a problem. The backup drive didn't mount. That was easy to diagnose -- I'd unplugged it. Probably when I was debugging my Aperture crash 3 weeks ago. Why didn't CCC report the error? Maybe it had crashed.
I wasn't that close to data loss -- but I was in a bad neighborhood. As paranoid as I am, I'm almost not paranoid enough.
It's good to have two fully automatic and completely independent backup methods. Data wants to die, and backup is still an unsolved problem.
 Incidentally, you can't easily report a purchase problem to Apple until they process a charge, and to reduce transaction costs they wait a few days before they process. This is very annoying! Also, the UI for reporting a purchase problem is suspiciously clumsy. More on that experience when I see what they do.
 In reality they common failure points of course - me, computer memory, etc. There is the older offsite backup though, so complete and total data loss is probably less than 1/1,000,000.
 Donationware. I donated. I wish donation ware apps would let us set a 'reminder' so I could donate yearly. I suppose I should just make donationware donations every year on my birthday against the apps I use.
 I'd love to have automated offsite backup too, but I've never foundan offsite vendor I trusted and I expect ISPs to eventually charge for bandwidth use.
- CrashPlan (or JungleDisk) instead of Retrospect 8? (1/2010)
- Online backup – the security problem (it’s not the encryption)
- backup (50 or so posts on backup)
- Retrospect 8.2 for OS X fails my latest review -- because it's been abandoned (11/2010 - I checked under the latest owner but it felt the same)
- Freeing up Time Capsule space – and documentation for Time Machine and Time Capsule (12/2009 - TM/TC are better quality now, but the documentation still sucks).
- Time Machine, Time Capsule and offsite backup (2/2010)
- My 10.6 iMac is crashing - a debugging exercise (2/2010 - using hardware test)
Update 12/21/2011: I was closer to the cliff than I realized.