Nikon's going after Canon with both barrels this year with the introduction of the D5. Traditionally the flagship sports-oriented dSLR in Nikon's stable, there are significant updates over the D4s for its essential capabilities, including a new 153-point autofocus system, a whopping maximum ISO of 3,280,000 and 4K UHD (3,840x2,160-resolution) recording.
As is typical of this class of camera, it's not cheap: $6,500 (I can't find UK or Australian pricing yet, but that converts to about £4,430 or AU$9,100). Though the price tag is hefty, Nikon has addressed a lot of the needs of sports and low-light photographers. It'll be available in March.