Originally Posted by
Offhand
We do not know if that is the case. SSC/TK were launched with TBC and they contained t5. Ulduar was not launched with Wrath (which is the only instance to date to contain t8 level stuff). We don't know the level of difficulty the Argent Colosseum will be. It could be like ZA, with a timed-event challenge/special mount, etc. OR, it could be a new level of content. Neither is confirmed.
And nothing says gem stat ratios have remained constant from TBC to Wrath. A pattern of one example is not a pattern at all.
EDIT: I would certainly like epic gems, but no where are they a guarantee. Seeing as Blizzard is dead set on balancing professions to be exactly equal at all times, it wouldn't be surprising at all to see +3 points of stat added to JC gems once epics are introduced.