The introduction of the Raid Finder in patch 4.3 probably means little to players who raid on a weekly basis with their guild. You get on at a predesignated time and attend the raid. Sure, it might be great for alts or doing older content, but for those of us who have stuck with our old guilds, trying in vain to grab at embersilk tatters, it could be a real guild-saver.
I have been running a guild that re-formed at the beginning of Cataclysm. I have watched players leave by the score to join higher-level guilds. They want in for the perks and the mere chance that they may be selected to be an alternate for heroic or new content, even if it's only once a week. Given our shifting playerbase, we have not been able to hold on to a full team that is raiding consistently. Our ability to progress through content has suffered. It seems most of the time our new members either don't have the time to raid or have no experience and very little willingness to put in the time to learn.
So what does the Raid Finder mean for us? The way I see it in my wildest dreams is -- autopilot.