inotify has been introfuced since the 2.6.13-rc3 kernel(http://beaglewiki.org/Inotify_Kernel) there is an easy migration document here(http://www.gentoo.org/news/en/gwn/20060320-newsletter.xml#doc_chap5) so why not adding einfo at the end of all the kernels ebuilds(can be scripted)? if there is too much ebuilds and that the problem will be that all users would re-download too much kenrel ebuild we may add this only on new versions ov kernel ebuild or new ebuilds or add it inside the "inherit kernel-2"
Everyone that installs kernel needs fam/gamin? I guess not. :) If such info belongs anywhere, then it's fam ebuild.