I'm looking for something very much like the Linksys WRV54G, but that's still in production and has OpenWRT support. Namely, I'm looking for a device with an IXP42x processor (266Mhz or 533Mhz), 8MB flash minimum, 32MB RAM minimum (preferably more!), at least two network interfaces (one WAN, and one LAN - preferably with a switch too), and of course 54G Wifi.
The WRV54G is ideal, but discontinued and doesn't seem to be supported. The NSLU2 fits the bill, but only has one network port and no Wifi. The Compex NP18A has been discontinued (soon to be replaced), but is quite expensive in comparison.