ZDNet.uk basically copies the comments from Steve Langasek in the recent announcement of platform support for Etch.
You can read their copy/paste and very few comments here
Debian Etch, the next major version of the Linux distribution, will only be available on eight architectures, with four getting the boot.
Steve Langasek, a release manager at Debian, said in a mailing list posting last week that the official release of Etch, which is due in December 2006, will not be ported to systems based on the ARM, Motorola 68k, IBM S/390 and Sun SPARC architectures.
Even better, you can check the original announcement here