For developers interested in Linux input and/or Wayland's input handling via the abstracted libinput library, there's a new mailing list thread. The new thread has been active since Wednesday and covers upstream developers discussing the way forward for tablet support for this library that's used by Wayland's Weston compositor, GNOME's Mutter compositor for Wayland, and others.
This libinput work comes just after its version 0.2 release that happened this past week. Overall, the code is progressing nicely.
Within Canonical's Ubuntu display server world with Mir, they just introduced a DPI surface attribute and other fixes within recent days.