I'm terribly sorry, but i fail to see how this raid finder only difficulty will make anyone happy.
I'm seeing its gear being labeled finder gear, people mocked for doing it and obtaining below everage tier pieces. Or even worse, people requiring raid finder achievs for normal mode raids or to join guilds.
The solution was right before your eyes.
Easier normal mode raids, for everyone to experience them, shiney and new but doable in a pug(or through the raid finder, same lvl of difficulty as normal mde, same drops).
Hardmode raids creepy hard, for those minority of players that can efford and like and want to do it the hard way, and get better loot, recoloured and more shney than ever.
i don't see why do we need 3 difficulty lvl, what is it for ? labeling casuals, mediocre, and good players ? some people will have raid finder gear, some other normal mode gear, and some other hard modes gear. further increasing the jealousy and unhappynes around.
players out of the raid finder will still hit a brickwall on normal mode raids, cause let's be honest, it's not the gear that makes the fight, but the encounter requirements, if u need 20k everag dps to beat a boss, and you're only capable of doing 17k, u just won't make it.
what relly changes in between having 400 itemlvl and 390 itemlvl is how other people look at you, and how you feel with yourself. which is what makes people stop playing, not being able to kill anything else than shannox on normal mode is crap, and bring players away, now you can have instead raid finder to kill more bosses, ye, but u will only feel better until you go hit that wall in normal mode again.
Noone wants gear easy to obtain(through raid finder in this case) they want to earn it, but in a way that is not heavy and doesn't require too much effort, which is entirely different from doing an easy mode raid.
They want normal mode, made easier. And be happy with their half a tier below heroic mode gear and bonuses and whatnot.
Hey, i will surely use this raid finder, even with my guild if it's possible to queu as a group really, easy mode sounds like a good way to experience stuff and get ready for normal modes, but really, i doubt i'll be any happy until i get at least normal mode raid gear.
And will be even more unhappy if by any chance i won't be able to kill anything in the new raid due to the fight requirements being too high, like it has been all along in this expansion. i'm just being honest, i havn't been happy in this expansion, cause it was just too hard, requiring too much from 9 different people where the skill range may vary incredibly, i've seen people doing barely 10k in 359 gear, and they are good people, with a family, a work, maybe not much time, people i play since ages, and it pains me to not be able tot ake them to a raid cause they are not good enough for it. cause distress in them, in me, in the guild.
making people happy should be your priority. a third difficulty ain't going to solve anything, quite the opposite, it will only provide people something to do for a little bit, that will ultimately leave then unhappy anyway.