I can give linking libkml up with GDAL a shot if you'd like. There is a setting in the options file to point at libkml. It doesnt look like its part of gdal. It may depend on how the app is using libkml - if its using it directly we may not need to link the two.
I agree w/ the libraries, that if we encounter a new one its a good idea to make a new issue item for it.