The summary about sums it up. It looks like PyQt4-4.8.4 (and earlier?) may need to depend on <dev-python/sip-4.13 or something like that. I had problems compiling pykde4-4.8.1 due to this. I didn't try PyQt4-4.9.1 with sip-4.12, but thought that adding in this DEPEND might save someone else some time when trying to upgrade. Someone in #gentoo-kde suggested I open this to track.
Dependencies added, thanks.