It appears that long-standing alpha and powerpc bugs 83825 and 67737 (no gvim in vim-gtk, caused by build-deps bug 92065) have been fixed in testing and unstable. At least, the build-depends have been fixed in the latest source packages.
However, I have no PPC or Alpha machine over the summer so I can't test for certain. Can users of these ports verify that vim-gtk/unstable includes a functional gvim? Then we can close the bugs on this 332-day-old issue. (Bug 83825 is duplicated in bugs 87291 and 95227.)