Hal support is indeed not enabled in i386 build (it is for ppc builds) on debian.corsac.net. I won't rebuild Xfce 4.4 for i386 with exo hal support enabled, as I don't really have currently enough power to do that more than once in a while.
But ema has begun to upload Xfce 4.4 package to experimental, so exo (with hal support enabled) is available on Debian Experimental packages.
If you want to test it, add experimental sources to your /etc/apt/sources.list:
deb http://ftp.fr.debian.org/debian/ experimental
main
Then update and install exo:
sudo aptitude update
sudo aptitude install libexo-0.3-0/experimental
sudo aptitude install libexo-0.3-0/experimental
You can also pick other libs from there, which are more recent than ones on debian.corsac.net.
As always, be aware that those packages are in experimental shape, so it may damage your system, kill your cat and make your SO go away. Be prepared!
Anyway if you encounter bugs, don't hesitate to tell us on irc (precising from where your packages come from).
Happy testing.