With LFR making raiding the easiest it has ever been, we seem to now be back at the stage where being in a guild isn't much of an advantage.
Sure, guild perks help, but I could join a level 25 levelling guild and get the same perks without having to join a raiding guild.
On the one hand, I think it's great - everyone gets to see end-game content, I can raid for 15min if I don't have time for anything more and if you want to stay with a guild of friends rather than an anti-social bunch of overachievers, it's fine.
On the other hand, it isn't so great when you're in a guild trying to recruit more for your raiding team - nigh impossible, in fact.
I'd be interested to see whether Blizzard thinks this issue is important enough to do something about it in the next expansion, or whether they believe that the LFR-casual-friendly approach outweighs the need for mid-level raiding guilds. I'm not sure I'm liking the fact that there are less than 10 people in guild chat these days (thank you, SW:TOR) and even though we may have a couple of regular PuGs that join our guild raids, it just isn't the same.