2009.02 comes with the following features:
- Kernel 2.6.28
- Ext4 support. Installation can be done on a ext4 root partition.
- Rescue and maintenance capabilities for Ext4 root partitions
- Fallback ISOs with the ISOLINUX bootloader, for those that have
trouble booting Grub-based images
- Several bugfixes in the installer
- Brought the included documentation up-to-date
- Inclusion of AIF (Arch Linux Installation Framework), the next
generation installer, currently under development.
I have never used Arch myself but I according to what I've read it is a very good distribution to be installed an old computers. If you are new to Arch, start with the Beginners' Guide.