Linksys has revamped the user interface and slightly changed the feature set since the WRT54G's review. Since this review is likely to also be well-read, I've reprised most of it here - with appropriate text and screenshot changes - so that you don't have to click back and forth between this and the older review. The Performance sections are brand-new, however, so if you're already familiar with the WRT54G's feature set, you may want to skip right to there.
The WRT54GS (GS) comes in Linksys' pre-Cisco purple and grey plastic box. All indicator lights are on the front of the box and are bright and viewable from a wide angle. All network connection indicators have been scaled back to single Link/Activity types for the four 10/100 LAN ports, WLAN (wireless LAN) and 10/100 Internet (WAN) ports. Power and DMZ general indicators (Diag has been dropped) round out the blinky stuff.
The DMZ indicator now properly lights whenever the DMZ feature - which opens up all ports to one selected LAN machine - is enabled. The WLAN light is now also a much better indicator of wireless activity, briefly shutting off when the WLAN link is passing traffic. It also extinguishes when you set the Wireless Network Mode selector in the admin interface to Disabled to shut off the router's radio.
Four 10/100 LAN ports, one 10/100 WAN port and power jack are on the rear panel, along with the Reset switch, which now serves only a reset-to-factory-defaults function. Note that all ports are auto MDI / MDI-X (though Linksys doesn't spec or mention this) which means they'll figure out how to connect to whatever you plug into them, including switches if you decide to expand the number of ports.
Linksys didn't include the wall-mounting plate that came with my original WRT54G, instead now offering it separately (as long as you want to buy ten of them). Also included are a CD with the User Guide (PDF), Windows-based Setup Wizard, trial version of Symantec's Norton Internet Security Suite and LogViewer application. You also get printed Quick Install and Parental Control Quick Install pamphlets as well as a normal UTP Ethernet cable.