For me one of the draws to vim isn't vim in its bare state, but vim with my plugins of choice, and I have yet to find a vim emulation plugin that loads the vim runtime, with the exception being eclim for Eclipse; unfortunately, the vim-mode for eclim is just vim with a janky plugin, and the embedded mode doesn't work on OS X because MacVim can't be embedded the way vim-gtk can.

There's a good one for IntelliJ called IdeaVim.

I tried solutions for Eclipse back when I used it, but I couldn't find one that I liked.

Well, you could try to use NetBeans with the vim plugin instead. The ability to use vim, plus the undocking windows, are what made me switch from Eclipse to NetBeans.

Got tired of tiled windows crowding each "perspective", and constantly reaching for the mouse.

If I cannot use vim's : commands or plugins, then merely implementing a few keybindings like hjkl is worthless to me.

That would be the world backward: it's like when IntelliJ or Eclipse do offer Emacs shortcuts (Emacs shortcuts being the stupidest things ever invented --and this comes as a long time Emacs user), completely missing the point.

BUT there's light at the end of the tunnel: there's eclim (eclim.org), which allows you to use vim (the real one) as the text editor for Eclipse. Or if you want you can run Eclipse in headless mode and then have vim transparently contact the (local) eclim server and suggest you, right in your vim, the autocompletion hints from Eclipse etc.