Success! Running Debian GNU/Linux on a dual-processor Intel Itanium 2 workstation. Screenshot here:

Debian GNU/Linux on Itanium 2 - TechIMO Photo Gallery

Had to sort out a few issues - enabling DRI support in particular - but otherwise the installation was not overly complex. Skimmed some bug reports, then deployed a few updates from the unstable repository, along with a little manual configuration work.