So I went through and pruned my f-list, but I removed only those people who (a) didn't have me friended AND EITHER (b) don't regularly turn up when I read my Friends page (i.e., people whose LJs have gone inactive or friends only) OR (c) don't have anything of major interest to me when they do turn up on my Friends page. So if you're one of those people, chances are you don't care anyway, since you don't read my journal. It wasn't an "OMG YOU DON'T LIKE ME, SO I DON'T LIKE YOU BACK!!!111" sort of thing, but rather an effort to make my f-list a bit more manageable. If we are mutually friended, then I didn't remove you.
If I defriended anyone who wants to be back on, just let me know. Anyway, I typically don't f-lock my posts, so it's not like you're missing anything. But I'm always glad to refriend! :)