Package management: pacman-g2 (command line)
No PAM problems/support (a'la Slackware)
Linux kernel 2.6 (no 2.4 support)
i686 or later CPU needed on x86
The latest documentation is here.
Supported architectures: i686, x86_64
Stable releases every 6 months
Security support for stable releases
Text mode installation
Offline installation, netboot install supported
Prebuilt CD/DVD, USB, TFTP images are available
Localization supported whereever it's possible
About 3000 source packages and (as of Februrary 2007) 3200 binary packages supported.