This will be a running thread as I like to try and keep everything updated....always have a backup
This is after a fresh flash and the gitpull that is on Page 5 of the beta thread....
pacman -Syu gets:
Packages (39): bash-4.3.030-1 curl-7.38.0-3 db-5.3.28-2 dbus-glib-0.102-2 dhcpcd-6.5.1-1
ethtool-1:3.16-1 file-5.20-1 filesystem-2014.10-3 gdk-pixbuf2-2.31.1-1
git-2.1.3-1 glib-networking-2.42.0-1 glib2-2.42.0-1 gnutls-3.3.9-1
gsettings-desktop-schemas-3.14.1-1 hostapd-2.3-1 iproute2-3.17.0-1 krb5-1.13-1
less-470-1 libldap-2.4.40-1 libogg-1.3.2-1 libpipeline-1.4.0-1 libsoup-2.48.0-1
libtiff-4.0.3-5 libutil-linux-2.25.2-1 libxml2-2.9.2-1
linux-firmware-20141009.0e5f637-1 linux-raspberrypi-3.12.29-1 mpg123-1.21.0-1
nfs-utils-1.3.1-1 openssh-6.7p1-1 openssl-1.0.1.j-1 p11-kit-0.22.1-1
pacman-mirrorlist-20141022-1 pcre-8.36-1 sqlite-3.8.7.1-1 tzdata-2014i-1
util-linux-2.25.2-1 wget-1.16-2 wpa_supplicant-2.3-1
I updated everything, and did the kernel renaming (save the original kernel with a new name like: linux-arch-rpi_3.12.26-1-ARCH.img.ORIG, rename the new kernel.img to the old kernel name: linux-arch-rpi_3.12.26-1-ARCH.img) and everything still seems to be working fine.
uname -a gets: Linux runeaudio 3.12.29-1-ARCH #1 PREEMPT Tue Oct 7 07:03:53 MDT 2014 armv6l GNU/Linux
YMMV...enjoy