I think the merging of config files would be a lot easier if it was a 3-way-merge, ie. a merge where you have the old default version, the new default version and then you own hacked version. Using a 3-way-merge you would be able to accept any changes made to the default config file where you haven't touched anything yourself and on the other hand know when you have touched something that is changed to something else in the new default config. You can use diff3 for this: diff3 hacked-config old-def-config new-def-config -m The problem is then, that you need to keep the old-def-config, but that should be relatively easy with ebuild/emerge, when a package is installed or upgraded the default config from that package should be saved somewhere (in /etc/.defconfig or whatever).
dispatch-conf seems to do something like what I suggested. *** This bug has been marked as a duplicate of 11763 ***
