Would be interesting, for working targets, to create a defconfig in the mainboard directory for that target. Then, as each mainboard is tested and known-good in Kconfig, people (and an automated tool) could easily see that we had a Kconfig-supported mainboard.
We could then define some threshhold (80%? 90%? 95%? ) at which the remaining mainboards would have to "convert or die" :-)
I can see a day when the targets directory goes away, along with the old config tool! Oh happy day!
ron