I kind of abandoned CD/DVDs for about 3 years in favor of hard disk backups, but I just got back into it because of the extra security of being able to send backups off-site in case of fire, theft, etc. I've burned about 120 DVDs in the last week and a half doing some long overdue backups. I'll probably do another 100 or so in the coming week or two, but after that it'll probably drop to 3-5/mo as I do incremental backups for a while. Maybe another full backup in 3 months or so.
My stash was kind of rotting as I've been off optical mediums for a few years. I was doing ~60 DVDs/mo from 2004-2008 as backups. I've currently got ~300 DVDs (mostly 179 new Taiyo Yudens remaining), ~80 CD, and a smattering of small square business card CDs and mini CDs. Many of the CDs are pretty ancient 8x Ricohs which don't even burn in my current burner for some reason (not sure if the media is bad or what). I'm not sure what the purpose of hoarding up media is though. Doesn't it go bad regardless of whether its been written to or not? Are you going to end up with a closet full of coasters regardless?
I hate to see optical media going the way of the dinosaur. It's really the only suitable medium for backups IMO. Hard disks hold a ton and are cheap, but have sensitive electronics, can't take shock, and have to be spun up periodically to prevent spindle lubricants from drying out. Flash memory is just plain scary -- it's so fragile just looking at it wrong can trash your data. Tape backups... do those exist anymore? Heh. They cost a fortune.