This will be of interest to a few only.
Question:
Can the new Airport Express give you broadband connection for a number of WiFI devices - AND an old Mac (Leopard or beyond) with no WifI card in it (so it has to be ethernet-cabled to the new Express's (first time) LAN port?
Yes it can given my experience. And I am no techie.
Of course, the above may not be news to some (or even many). Still it's just lovely news for those of us who have an Apple WiFi device and an old Mac with no Wifi card in it. AND we want them all to work on the same Express network.
I set up the Express first with a WiFi device: A late WiFi 2009 iMac. It was powered but no ethernet cable was attached to it. What Apple says is right -- about one minute for set up. Cables are, however, needed from the Airport Express to power (the cord is provided by the Express purchase) and from a computer friendly "modemized" cable (however done) to the WAN port of the Express.
All worked well. The Express seems to be a router for both Wifi devices and cabled no WiFi computers. (I suppose -- without testing -- a number of no WiFi computers can come off the LAN port with a switch.)
