There's been no official announcement from the Cubs, but I have learned that they will be hiring Dave Martinez to serve as Joe Maddon's bench coach.
This "getting the band back together" move reunites a tandem that had served together as manager and bench coach for the Tampa Bay Rays for the last seven seasons, from 2008 through 2014. During those years, the Rays made the playoffs four times and went to the World Series in 2008.
Martinez was passed over for some managing gigs -- including by the Cubs when they hired Rick Renteria a year ago -- and was also not considered to replace Maddon in Tampa Bay, making it a logical move for him to resign his post, get permission to seek work elsewhere, and join up with Maddon to help make Maddon's transition to Chicago as seamless as possible.
Martinez also brings to the team four years' worth of experience as a Cubs player, from 1986-88 and again in 2000. The circumstances under which he left the team by trade in 1988 don't need to be rehashed now -- that's long-ago and settled. Martinez is well-respected as a coach, and while he might not have what it takes to be a manager based on being passed over several times, he'll surely help Joe Maddon in the same way he did in Tampa.
Hopefully the results -- four playoff berths in six years -- will also be repeated.