If this change goes through, it seems that the feats of strength from each tier will be separated again. The rewards still remain identical.Ahead of the Curve: Garrosh Hellscream (10 player) Defeat Garrosh Hellscream on 10-Player Normal difficulty, prior to the release of the next tier of content.Reward: Reins of the Kor'kron War Wolf.
Ahead of the Curve: Garrosh Hellscream (25 player) Defeat Garrosh Hellscream on 25-Player Normal difficulty, prior to the release of the next tier of content.Reward: Reins of the Kor'kron War Wolf.
This seems like an appropriate change if the intention is to differentiate the contents. The 'normal' achievements seem unchanged as of now so the players solely interested in achievement points are not pressured into raiding both of the formats.
EDIT: The Cutting Edge achievements also have two different versions.
http://ptr.wowhead.com/achievement=8401
http://ptr.wowhead.com/achievement=8400