In to "cheat" the (for me) unnecessary texlive dependency freetype-1*, I have included the current media-libs/freetype-1.3.1-r5 in /etc/portage/profile/package.provided. Unfortunately, this has the effect, that media-libs/freetype:2 is never updated automatically and even refuses to re-emerge until I remove the above entry in package.provided. I understand that it is not possible to read the slot information "automagically" from the entry in package.provided, because it is then unclear what to do with version numbers not in the portage tree anymore. However, I guess it should be possible to tell portage that a certain entry in package.provided just refers to a specific slot, i.e. an entry like media-libs/freetype-1.3.1-r5:1 or perhaps media-libs/freetype:1-1.3.1-r5 should be possible (currently, both gives only an "invalid atom" message, of course).
*** This bug has been marked as a duplicate of bug 142941 ***