The first Patch Tuesday of 2016 includes a new cumulative update, KB3124263, that will push all Windows 10 users to Version 1511 (OS Build 10586.63).
Microsoft has not published the KB article yet however, it is not expected to contain much additional info beyond general performance updates and bug fixes just like past cumulative updates they have released for the OS.
Patch Tuesday is now becoming the defacto cumulative update day for Windows 10 as the company is settling into their Windows as a Service routine.
As you can see, the build number is a very small incremental bump from the previous active release of Windows 10 so I suspect it will not have any new features but truly be focused on performance and bugs as mentioned earlier.
While Microsoft continues to maintain Windows 10 they are also working on the next big update to the OS, Redstone, which Windows Insiders received the first build of before Christmas. That preparatory build has set the stage for Insiders to see the first elements of Redstone in a new build sometime later this month.
Microsoft has promised those builds will be released at a much faster pace than Insider builds last year and I know Insiders are excited about getting started.