It sure can! And you can also get different chipset architectures, as well. Here's a few sample lines to give you the idea:
Just use your /apt/sources.list file as a model, changing the 'deb' prefix, as well as the codename for the release. I currently mirror 4 releases and 3 architectures (use 'deb-armel' for the ARM processors).
# Just a few sample lines from an /etc/apt/mirror.list file
# Precise on i386
deb-i386 http://archive.ubuntu.com/ubuntu/ precise main restricted
deb-i386 http://archive.ubuntu.com/ubuntu/ precise-updates main restricted
# Precise on amd64
deb-amd64 http://archive.ubuntu.com/ubuntu/ precise main restricted
deb-amd64 http://archive.ubuntu.com/ubuntu/ precise-updates main restricted
# Oneiric on i386
deb-i386 http://archive.ubuntu.com/ubuntu oneiric main restricted universe multiverse
# Source file entries can also be used
deb-src http://archive.ubuntu.com/ubuntu oneiric main restricted universe multiverse
# Even Debian Squeeze (since Debian also uses .deb packages)
deb-armel http://ftp.us.debian.org/debian squeeze main contrib non-free
deb-armel http://security.debian.org/ squeeze/updates main contrib non-free
Remember that the default architecture (if you just use 'deb' is for the architecture of the machine where apt-mirror is running, so if you have old and new machines, you may want to get both. You can determine which architectures you need by typing
Which will return 'x86_64' (deb-amd64), or 'i686' (deb-i386), or 'armv5tel' (deb-armel).
For each distribution ('precise', 'oneiric'...) and architecture, you will need to plan on downloading and storing about 30G. At least apt-mirror makes that pretty efficient.