They were experimenting with an Enrage that procs on special attack crits only, and for that purpose completely removed Overpower's crit chance for a while, and buffed it's weapon damage to be just below Mortal Strike. It felt really awkward not seeing your Overpower crit (people were in questing greens with less than 10% crit chance).
Was in response to OPs suggestion of removing the bonus crit from OP to allow better scaling with crit chance, which in itself is a fairly good point. The extra crit chance from Recklesness is wasted on Overpower, and Slam is a very expensive ability to replace all Overpowers with during Reck. Would be kind of nice if Overpower got the Chaos Bolt treatment in which all crit past 100% was turned into extra % dmg done.