5.0.4 Warlock T13 2 Piece Bonus vs. Grimoire of Supremacy

So I noticed today, with the new patch on live servers, that by selecting Grimoire of Supremacy in the warlock talent tree my 2 piece set bonus was basically useless.

http://www.wowhead.com/spell=105888

It seems that since the talent changes your infernal into an abyssal and the doomgaurd into a terrorguard, that the 4 minutes off the 10 minute CD no longer applies.

Now the abyssal and terrorguard do 20% more damage but is that enough to make the 2 piece too OP? Or is this not working as intended?

Obviously once I gear up in MoP it won't matter, but I am curious if anyone out there knows if this is intentional or an oversight.

-Thanks

Most likely, it's an oversight and frankly, I doubt it's a high priority for the devs to fix a talent synergy with a set bonus that won't be supported anymore in 3 weeks. Besides, it's not like the set bonus is wrong, it still does exactly what it says it should :)

Playing Affliction last night, felt a lot like playing my Shadow Priest.

Long time lurker with a quick question for warlocks.

I have a Warr Tank/Dps, Shaman Healer/Melee Dps, and Hunter Dps (rotting since mana went away :/ )

I started a Demon Lock about 4 months ago. It was a project to see how casters worked but I got to about level 74 and I didn't much care for him. Not much fun standing around casting at stuff. My heart is being in the middle of the action.
However, post patch, I saw the glyph for Dark Apothesis and thought, this is interesting! So, I went back to him up again after the patch and had a blast playing pseudo-melee. Leveled him to 85 that way. It was pretty awesome.
Sadly, all the heroic random groups I got into, while understanding of me being a new 85 and a demon lock, said that aside from maybe caster tanking (IE: Gruul's) that Destro or Aff were the way to go for dps.
Does anyone know what the long term intent/purpose was for the glyph? Other than caster tanking a boss add or something at some point... If demon is not the way to go for dps, is there a guide around here with patch changes that I could use to help me with me with picking up a different spec?
I appreciate your time.

Personally, it seems to me that all the specs for multiple dps classes are very competitive. My frost spec on my mage is fairly even with my fire and a guildie's arcane. The hunter specs seem close enough that you can play the one you like, etc. If demo is what you are enjoying, I doubt that it will be far enough below the other specs that it would be considered not raid-viable.

A lot of times, just enjoying a spec really well will make up the difference. At the start of Cata, BM hunters were considered kind of bad. One of our guild hunters loved the way it played and was conpetitive with any other hunter I saw at the time.

Really, if there is a 5% difference in a spec, class knowledge, focus and general give-a-shit can make up that difference over someone with the "best" spec who doesn't have those to the same degree.

Yeah, I get that.
I've long understood that what happens in LFD/LFR is best taken with a grain of salt. I've really enjoyed the Demon Lock thus far (and I knew that my DPS would be lacking, I had some 333 spirit blues for the ILevel boost to get me into the LFD with some guildies) so even in another spec I'd be subpar as I'm geared now.

What I am most curious about though is if anyone can speculate what the intent of being a Lock Tank would mean for MoP. With the glyph physical/spell damage reduction and increased threat and many short damage reduction CD's could it get to a place where it'd be a viable tank? If not, I don't get the threat increase, but if it is the case, I'm real interested and I think it'd be a pretty amazing thing.

The other question about the guides was so that I could try a different spec to try to appease my fellow LFD/LFR masses and hopefully get some new insight on casters, work out a good rotation for "resource management", and hopefully with the patch changes find more enjoyment (than just tanking) from it.

Until then, I'll try to get my wife (pocket healer) and some guildies to roll with me as a Demon to see how far I can push it. Alas, I cannot queue as tank yet.