While running Knoppix with the 64 bits kernel version works very well for me, Knoppix is still, basically, a 32 bits system. And, according to Klaus K, it will probably stay that way for a while. Maintaining 4 (64/32*CD/DVD) versions instead of 4 would probably more than double his work (according to him, and I think he should know), and I don't think that is a sensible use of developer resources, even if he had been willing.

For some purposes, we may need "pure" 64 bits. Video/image editing, running virtualization software, doing data analysis on large data sets are some examples.
It turns out that creating a 64 bits version is probably much more of an administrative than a development task. If we make a minimum of modifications from standard Knoppix, we can mostly substitute Debian's 64-bits packages, and most of the Knoppix-specific software is architecture-independent scripts. So, it may go with just a few new compiles, and I tend to think that most of the work involved will be to set up some efficient administration scripts. Having assembled all the necessary packages, it should be mostly plain remastering sailing to create a new cloop/squashfs image. But one has to try it to tell.

While it might be tempting to do a lot with setup and package selection in this context, I would try to do as little as possible. For my own use, it would imply adding some more scientific programs, a bit like Dirk Eddenbuettel's Quantian, and remove quite a few games and little used programs, to free up space for program adding and remastering.

Also, such a version could have two cloop/squashfs images: One with Open Source programs, and one with non-free software. There is still support for this in the init process.

While a more experimental version could well be called "Geek-Knoppix", as suggested before, the 64 bits version might perhaps be called Server Knoppix, because server use will be an important application area.

I would like to stress that this is not any kind of fork or fundamentally new derivative. I think it should work exactly like standard Knoppix whenever possible, and that additions should not modify the ordinary ways of doing things. We might add a few scripts and other programs, and some new cheatcodes, but that should be all. In practice, a user could install both 32 and 64 bits versions on, for example, a USB harddisk, and then choose which to use at bootup, just like 32- and 64 bits kernel versions are used today.

I don't know exactly how much work this will be, but I imagine it won't have to be a very huge task,so a few volunteers ought to suffice.

Or am I completely mistaken?