Skylake Mac Notebooks May See Staggered Launch in 2016, Led by MacBook and 13" MacBook Pro - Mac Rumors
Given that Skylake chips have been announced for both the 13-inch and 15-inch MacBook Pro, there does not appear to be any reason for Apple to stagger the release of its notebooks this year. But, perhaps in line with its 2015 release cycle, Apple may plan to give the current 15-inch MacBook Pro a longer shelf life before replacing it.
Guess that means they won't make any substantial changes to the Pro I currently have..