kde-misc/kcm_tablet works fine with x11-drivers/linuxwacom drivers but fails with x11-drivers/xf86-input-wacom. Since xorg-server 1.7.x requires the newer drivers (or rather x11-drivers/linuxwacom does not work xorg-server 1.7) that means that kde-misc/kcm_tablet does not work with xorg-server 1.7.3. It appears that kcm_tablet needs xsetwacom to work and this is not part of x11-drivers/xf86-input-wacom. In addition even with x11-drivers/xf86-input-wacom installed kde-misc/kcm_tablet-1.1.1 builds and installs without any error messages. Reproducible: Always Actual Results: I get a "No tablet device was found!" message when I run the tablet configuration applet. Expected Results: It should find the tablet and allow me configure it.
Problem solved, forcing linuxwacom instead of xf86-input-wacom in the ebuild now. The kcm_tablet will be removed from tree at the same time with linuxwacom, when the time is due, unless they release a version that works with xf86-input-wacom by then.
The actual problem is that x11-drivers/xf86-input-wacom is missing the wacom utilities that are needed by kcm_tablet. This is an issue with the x11-drivers/xf86-input-wacom ebuild that needs to be fixed regardless and I have opened another bug report on that issue. See Bug #296780. Rather than removing kcm_tablet the ebuild should only work if x11-drivers/linuxwacom is installed until such time that the x11-drivers/xf86-input-wacom ebuild also includes the wacom utility programs, At that point it should work if either x11-drivers/xf86-input-wacom or x11-drivers/linuxwacom is installed.