I have three Pogoplugs on my desk that have all been reloaded with Arch Linux and are handling miscellaneous tasks on my home network, including handling DNS and DHCP.
Plug #1 (P21) is an ARM v6L (Oxsemi NAS).
uname -a: Linux catslair 188.8.131.52_SMP_820 #100 SMP Sun May 29 04:53:45 EDT 2011 armv6l ARMv6-compatible processor rev 5 (v6l) Oxsemi NAS GNU/Linux
Plugs #2 and #3 (E02) are ARM v5Ls (Marvell SheevaPlug).
uname -a: Linux wilykit 3.1.10-4-ARCH #1 PREEMPT Wed Feb 29 04:02:24 UTC 2012 armv5tel Feroceon 88FR131 rev 1 (v5l) Marvell SheevaPlug Reference Board GNU/Linux