BoK brings up something I've thought a little bit about lately: their guild will occasionally run an encounter "blind," which means they'll go in without researching or learning any boss strategy ahead of time. This is generally something that only the highest-level guilds often do, and even then only on the PTR -- by the time bosses hit the live realms, their abilities are usually posted online somewhere. But some guilds enjoy a challenge, and doing a raid without knowing what's coming definitely keeps you on your toes. A lot of raiders think that's actually the "right" way to do it -- Blizzard's game doesn't come with strategies installed, so if the designers created the fight correctly, it should be clear, just from watching buffs and boss animations, what to do during a fight.