This seems in-line with Blizzard's intention of making Discipline a viable main-tank healing tree. Unfortunately, Discipline (as of current) lacks the throughput and mana longevity to really keep a main tank up and running, due to the simple fact that the majority of the Discipline tree % raises are focused on boosting the strength of Power Word: Shield, a non-spammable spell that brutalizes rage generation if it were used in the quantities they want it to be. Now, with the Imp. Fort. changes, you either end up with at least one gimped Holy priest (but we've been used to this for ages due to needing one person going 28/33 for Imp. DS) or bring along a Disc Priest for your buffs. With all the other changes they've made about how they want to remove the requirements for one "off-spec" being required to raid, and gutting a lot of people's raid-utility trees and giving multiple classes the same buffs, this really feels to be going in the opposite direction. It used to be that all Priest builds had Imp. Fort guaranteed, but with this change it doesn't look like Shadow builds will pick it up, depending on our mana longevity towards end-game.
Fortunately, it appears (at least so far) that most Heroics and raids can be handled without meditation, using only Dispersion and the Shadowfiend, along with our personal regen from IST and no longer needing to re-cast SW:P. If this remains, we'd have no need to pick up Mediation and could instead grab Imp. Fort. and Inner Focus. However, if 3/3 Meditation becomes necessary, it will force Spriests and guilds to make a choice between having Imp. VE and another priest with Imp. Fort. The obvious choice here is Imp. VE, as (so far) it has not had it's party health restoration mechanic changed, and we've had our personal DPS increased to be on-par with that of other caster DPS classes. This would, strangely enough, make an Spriest an optimal addition to a Melee DPS/Tank group, as VT is now raid-wide, as are most of the other buffs (Windfury being the prime example, which is now a raid-wide Haste buff).
On the bright side, however, Imp. DS was nerfed pretty hard, making it no longer necessary to have one 23/38 priest, as the buff no longer scales with base spirit. So, really, unless they make Imp. DS scale again (which would be obscene at the L80 spirit amounts), or give people absolutely no reason to bring a Disc healer on raids. Now, I'd be perfectly fine with Disc not being a raiding tree. It's our PvP tree, really, most people are fine with it. Plus, using it as your MT healer, the only place where it has comparable throughput to a full Holy priest (less than 10% lower) ends up murdering a tank's threat generation. All this really does is force Holy priests to sink more points into Disc, the exact opposite of what the dev's have said their intentions were (I.E. streamlining talent trees and consolidating bloat) as well as forcing people to bring along yet another off-spec for "raid optimization".
