On the second working day of the year, Apple has just released the third beta versions of iOS 11.2.5 (compilation 15D5049a), from macOS High Sierra 10.13.3 (17D29a), from watchOS 4.2.2 (15S5536a) and the tvOS 11.2.5 (15K5544a) for developers.
The second beta for macOS 10.13.3 came out on December 18, and the other three systems the next day.
From what we've been following since their testing started by Apple, these updates won't bring anything very significant / visible beyond the traditional bug fixes and general improvements. However, if something paints you, we will notify you as always.
Soon, these new builds are also expected to appear for members of the Apple Beta Software Program with the exception of watchOS, which does not participate in it.