Microsoft: trade in a PS3, Xbox 360 E or S, get $100 off an Xbox One
Well thats one way to overcome a price gap. For a limited time, the Microsoft Store will give you $100 of store credit when you trade in your PS3 or Xbox 360 E [or S model]. The offer runs from 23rd January till 2nd March 2014, or while supplies last, and is exclusive to the US (including Puerto Rico) and Canada for the moment.
Just to hammer the point home, Microsoft has also mailed the below to a number of subscribers, via NeoGAF.