This afternoon I went through my extended blogroll, clicked every link, and 1) verified the site is still there (most were) and 2) verified the blog is still being updated (many were not). I deleted all the dead and dying links.
I find the shorter someone's blogroll, the better. I like following people's recommendations. But if you have 200 sites in your blogroll, are you honestly recommending them all? I doubt it. If you simply link every site you've ever visited (or every site which has ever linked to yours) then your blogroll doesn't mean anything. It is simply using up bandwidth. I think anyone who has over 50 sites in their blogroll should clean it up!
I while back I decided the best solution was to keep my on-homepage blogroll short, limited specifically to the sites I visit every day. (Nowadays they are the sites whose feeds I subscribe to with SharpReader.) And I moved all the other sites I like onto my extended blogroll. So if you're in the mood to check out some new sites, there you go... And each time the home page is loaded, I pick two sites at random from my extended blogroll and link them at the top; my "blog roulette". So you can serendipitously discover new sites that way...