Well, it's been a pretty exasperating few days, but I've successfully gotten my old (2006/1,1) Mac Pro set up to triple boot Lion (with a 64-bit kernel), OpenSUSE 12.2, and the Windows 8 Release Preview.
First, I set up Lion. I followed Jabbawok's Mountain Lion guide exactly, with one exception: since I was installing Regular Lion and not Mountain Lion, I didn't need to alter OSInstall.mpkg to skip the motherboard check. (As far as drive bays: I put the installer hard drive in bay 1 and the Lion drive in bay 2.)
After this I found that I could only get the 64-bit kernel if I used Chameleon's flag for Safe Mode (-x). Otherwise I got a blank gray screen on my helper card and a white screen with a frozen mouse pointer on my main card. This fixed itself once I yanked the helper card -- but I'll get to that in a minute. If you've got a helper card and you're following this guide, don't remove it until you've got all 3 OS's installed and get a nice clean GRUB menu when you boot. (Or a stupid-looking light-gray-on-bright-green GRUB menu, as the case may be.)
Anyway, after setting up Lion, I set up Boot Camp and tried to install Win8 (on a drive in Bay 3). I got the ol' "Select CD-ROM Boot Type" prompt where everything froze and failed to recognize any input.
I'd dealt with this years ago when I first set up Windows 7; I had to bootstrap my install disc. I decided I would just as soon not fuck with that procedure ever again, so instead of bootstrapping Win8, I used my already-bootstrapped Win7 disc to install Win7 and then upgraded to the Win8 preview from there.
And then I installed OpenSUSE (over the Lion installer partition in bay 1).
The OpenSUSE install DVD gave me the same "Select CD-ROM Boot Type" prompt freeze, so I tried the OpenSUSE KDE LiveCD -- that one worked just fine.
And after I'd installed OpenSUSE, I found that my computer had set itself up to automatically boot straight to the GRUB boot prompt. And, better still -- it had correctly set up Windows and both 32- and 64-bit kernel boots for OSX. Chameleon was totally redundant and unnecessary by this point.
The trouble? GRUB had the same problem Chameleon had: OSX would lock on boot unless I ran it in safe mode.
So that's when I popped out the helper card.
(Don't know what a helper card is? Then you don't need to know about it. But the gist is this: my Mac Pro came with a GeForce 7300GT graphics card. Last year I upgraded to a GTX 570. While current versions of OSX do recognize the GTX 570, the EFI boot firmware does not -- so I needed to leave the 7300GT plugged in to see the boot menu.)
Once I popped the 7300GT, everything worked great -- the GRUB menu came up, and booted any of the 3 OS's without any trouble. Success!
Or at least, success until earlier today when something got fucked up and broke everything and I spent my entire day trying to fix it. Ultimately it appears to have been a weird fluke -- I think my partition table got corrupted somehow, because I found that even a format/reinstall didn't fix the problem; I had to actually repartition (the Chameleon/OpenSUSE drive) to get it working again.
So that sucked. And is the second time in two days I found myself chasing down help pages for the last line of a boot log only to find it had nothing whatsoever to do with the actual problem I was having. What a damn bummer.
The upshot, though, is that I've got a 64-bit kernel working in OSX, which should let me set up the RAIDZ array I wanted to put together for my grandmother's home movies.
And last night I played Mass Effect 2 for an hour or so without getting a BSOD. Could be just a coincidence, but I'm hoping that removing the helper card and booting from GRUB instead of EFI fixed the constant crashes I'd been having before.
Next I'll try it under WINE -- maybe I won't have to reboot to Windows at all anymore.
As for how I feel about Macs, Windows 8, and OpenSUSE...well, those are all ripe topics for another day.