I just found on Planet Debian the following:
zakame@zaks:~$ sudo aptitude install xserver-xorg xlibs xlibs-dev
Worked without a hitch! A mere X zap, and presto! X.Org!
Kudos the Debian X team! =)
so my long-winded instructions below may no longer be needed
 -- Xorg has made it in to Debian Etch --- the instructions below are superfluous for that flavour of Debian. -- ThomasAdam
Peter Salisbury recently gave the URL to an unofficial Debian repository for X-Org. I decided to have a go at installing it on my system and this is what I did:
Edit /etc/apt/sources.list and add the url deb http://people.debian.org/~dnusinow/xorg ./ to the existing lines. I then commented out those lines for the time being leaving just the new one.
Run apt-get update to get the package listing for xorg
I then moved the package listings from /var/lib/apt/lists to a temporary location leaving only the one for people.debian.org in place. I did this because I'd found that having the other lists in that location confused aptitude when I tried installing x-window-system and aptitude wanted to install the old version. apt-get may not get confused but I didn't use it
then followed the following sequence of removes/installs:
aptitude install lsb-base (this may already be installed)
aptitude remove xserver-xfree86 xserver-common
aptitude install xserver-xorg
aptitude remove xfree86-common (I found that if you did this step too soon it wanted to remove all the installed X applications)
aptitude install x-window-system
Once all these packages were installed there were a number of 'held back' packages so an apt-get dist-upgrade updated the rest of the X libs etc.
The installation migrated my XF86Config-4 to a new xorg.conf and various other config files as well.
finally edit /etc/apt/sources.list and uncomment the lines previously commented out and move those lists back to /var/lib/apt/lists. This step could be left out as they will be recreated next time an aptitude update is run
running startx then loaded X-Org without any problems