I believe this is changing to meet biz travelers demand.

My guess (WAG) is that all major and most minor market airports will have wireless availability (paid or unpaid) this year or next. It is simply too important to the biz travelers that airlines want most.

Being centralized is usually not a problem as Murphy`s Law requires that if you land at gate 10, you will connect out of gate 56 (DFW) -- the tram service is down and you decided not to check that big bag this trip.

Also, if you have the choice of an 1.5 hour lay over in Nowhere, USA without internet access or the same lay over in an airport where you knew you could log on, which do you pick when flying longer distances where you have many airport options? or if major airline A has a wireless router in their terminal (or row of gates), and major airline B does not, which do you pick? It does not take long to know which airports are better than others with internet access.

IMO, this will become a marketing advantage for those airports / airlines / terminal businesses that spend the money.

John