Hi The new kernel 2.6.14 went up to testing, some major arch changes were done with this release. This kernel replaces the -scsi kernel and introduces full initrd support.
That means that ALL of you out there need to modify your bootloaders to use the initrd, or else you run into a kernel panic. Would be good if you have the arch install cd by hand, to be able to fix your system if something goes wrong.
To configure your initrd change /etc/initrd.conf to your needs and run 'mkinitrd auto' afterwards, else a basic initrd is used with all possible modules.
All subsystems should work (crypt is in developement atm, and will probably not work yet). I could only test IDE systems, so all others are welcomed to report success on SATA,RAID or SCSI devices.
Update: Please note that you will ALSO need to check your /etc/fstab and make sure that you don't use DevFS style names anymore. All names need to be the old happy kernel style like /dev/hda3.
Update: See the initrd wiki page for a quick tutorial on how to customize your initrd for your system.