Seeing as I have broken everyone's access to the main server at work by blowing out the IP quota by downloading the DVD ISO of the new Mandrake 10 for Itanium 2; I should at least write a few notes.
The installation was on a stock rx2600 with nothing really very interesting. The first problem was that it doesn't seem to boot from the EFI menu. This was easily fixed by slipping into the EFI console and manually booting the elilo included. This leads into the second problem, which is that by default the console goes to the VGA output which isn't great when you're using the managment card (as would be the usual case with a Itanium machine, I'm guessing). This is also easily fixed by appending console=ttyS0 ... but the default elilo boots straight into Linux without giving a chance to specify options, so you have to quickly break into elilo while it's decompressing the kernel.
At this stage, I managed to boot the installation. I just kept pressing enter until it stopped, when I realised that it was launching the X11 installer. This is bad choice for an Itanium machine ... especially for distribution aimed at clusters. I was left with no apparent way to get the installer working ... at a guess I decided to add text as a kernel command line paramater, which seems to drop you into the text installer.
You have to press enter each time it loads a module, and it seems to be loading different modules than it says it is.
The text install gives all sorts of whacky characters and highlights don't work correctly. This might be a terminal setting for the managment card, but I'm not sure.
Once I figured out how to tell the partitioner to auto-invoke and just partition the disk how it wanted, the next step simply hung, doing nothing. I restarted and tried as best I could to manually partition, and it still hung doing nothing. I tried again telling it to use the existing partitions, and it still hung.
So I currently haven't got any further. I'll update this if I ever do (I'm trying to subscribe to the beta list but it doesn't seem to exist), but so far the Debian installer is looking pretty good.