Well, Ret player is not only about DPSing. We do good DPSing, on my guild i was top on damage on nax (undeads) and now in ulduar i am going on on 2 - 3 spot since some fight need you to run away ( = not dpsing). But also, having the ability to regain mana for eveyone is a blessing. My guild was doing Razor in Ulduar and the healers were runing short on mana. When i get in the raid, the situation changed. More mana for everyone plus healing from JoL. It makes a huge diference.
So, even if i were 4 or 5 on dpsing, all the ability we put for the raid it compensate it. 1 blessing, JoL, replenishment, aura, reduce threat ability, Repetance.
There just 1 thing we lack. We suck with interrupts ; ; sad but truth. Warriors and rogue have the game in there, and sadly, some bosses in Ulduar you need to interrump them or it mostly be a wipe or healers will go oom.