Am now running Jaunty on our MacPro alongside Leopard Server, in its own little container. We can talk to it locally and get hardware acceleration, or we can talk to it more slowly over RDP.
It installed, well, I won't say shockingly easily, and I did have to change my deb sources to anl.gov, but lvm is back in the installer, and it installed with everything working but XWindows. After fiddling with X a bit, I realized it was probably best to let Vritualbox handle whatever magic it does there.
But it's got support for my Wacom in el Gimp and I can't wait to start using it as a musical device.
As for all that other stuff, like getting Nexenta running and OpenSolaris (and maybe even nebooting off the Mac across its private network). I am in general, just really super pleased.