The very first item in Mark Pilgrim's rules for aggregators is simple enough and deals with HTTP response handling:
301 Permanent redirect: MUST follow, SHOULD check new location thereafter. Check Location header on reply for new address.
Does Bloglines deal nicely with this? No, it doesn't even follow the redirect in many cases, for example Russ's old feed does a permanent redirection to a new url. I (and 3093 other subscribers) to the old feed haven't seen any new items from this feed on Bloglines for weeks.
If you want to see how well Bloglines is working, point it at this series of tests.