Hi after hanging around on irc, i see some problems arise with the new update:
Remember this points: devfs is removed from kernel26, get ready for udev. the /dev/discs entries will not work anymore on boot prompt. Please change it according to kernel26 install message.
Sound issues: 2.6.13 introduces a new alsa update. If you have sound problems, please remove your alsa entries from /etc/modprobe.conf and rerun alsaconf.
If your system hangs on boot after upgrade on loading modules (perhaps you use hotplug or lshwd), try to use "init s" on boot prompt to be able to repair your rc.conf and or modprobe.conf.
Please be patient until the mirrors are fully synced. Today is bugsquashing day so join #arch-bugs, to help us to find/solve issues.