I think it would be good to have some tool to check dependency libraries in *.la (/lib, /usr/lib) files - just if the path exists. I just updated gcc from version 3.3.5 to 3.3.6 on one machine, but dependency_libs of some *.la files contained path to 3.3.5 and as libtool took this dependency the compiling of other packages got broken. Revdep-rebuild didn't catch this problem.
Support for checking .la files added in >=gentoolkit-0.2.2-pre3