when the express was released i thought it would replace it. but when i got mine i noticed that in some network topographies, it can not replace the extreme base station.
the one thing i mean is that the express does not have 2 ethernet plugs. so you can not plug a router into it and share that with your videogame console or other wired computers.
this is not a big deal if you are the sole user of your airport, of it you have wireless cards for everything.
i have my powerbook (airport) and i have an xbox. so i either need the extreme to plug the xbox into, or i plug it straight into my powerbook.
one thing i have thought about, but don't know if it will work or not is plugging a router into the cable modem, and then the airport into the router.
any ideas about this one?