I've pruned various defunct or defunct-seeming sites from my various blog rolls. Most are still available in a new section further down.
I've kept some that have a history of dormancy, e.g. Hospital Food. They may or may not be moved at a later date.
Some entries have misleading dates. The Flickr version of Texts from last night is updated several times a day, but the feed I'm getting is updated only if someone posts to the discussion. If the folks at Not Hired haven't received a truly awful resume in some time they'll post a classic, and that will get tagged as being a year old. The Horse Head Huffer blogs (Spare some LOL, What the Face and others) have dates all over the map.
I'll probably be adding new sites to the various blog rolls in the relatively near future.