RetroChallenge is typically done in January and July. I would expect to see them start to do stuff with it.
When it was first started in either 2003 or 2004, it was "haha, see what you can do with a 6100" which even then wasn't.... toooo much of a stretch if you put 9.1 on it and you had a G3 upgrade, maybe a lot of RAM, and possibly either a file server or a big SCSI disk installed.
Today, ten year old machines are a lot less of a stretch. For reference, in 2006 you could buy dual-core notebooks with support for "about 3.5" gigs of RAM (on the Intel i945 chipset) and SATA disks. On the desktop side of things, you're looking at really fast Pentium 4s on 915-945 chipsets with similar "about 3.5 gigs" usable RAM ceilings, plus support for even newer graphics cards via PCIe slots.
On the Mac side of things, you won't get the most recent version of OS X on that hardware without basically hackintoshing it, but a lot of people say that 10.5 and 10.6 are still perfectly usable online. It depends on what you are doing. Except for online work, there's no reason I couldn't do my photo and video editing and all of that on a good G4 or G5 in 10.4-10.5 and contemporary apps.
"Do neat stuff" (that and, do it with computers that are now more than ten years old) is a more realistic overall idea for RC, I think. That said, it really split out and started doing its own thing pretty soon after being launched. This subforum is mainly here for vestigial reasons.