All quiet at the check-in counter: is anyone there?

Is this the next step toward charging flyers to talk to a human being when they check in at the airport? Not that that's such an outlandish possibility; Ireland's Ryanair has spoken about eliminating check-in personnel from the airport entirely as they drive passengers to the web for more and more functions; even South Florida-based Spirit Air has mulled the unstaffed airport.
Now the two 'U's, United and US Airways, say they want you to pay those checked-bag fees at home when you check in for your flight on-line and print out your boarding pass. If you tell the carrier from home that you'll be checking a bag - $15 for a first bag and $25 for a second bag - it will cost $5 less than if you just bring the bags to the airport and pay the fees there. Or in other words, it will cost you $5 more, $20 and $30 respectively, to do the airport thing.
When you do it on the web, the airline's people spend less time on you, goes the argument. But take the premise to its logical conclusion: the more passengers do from home, the fewer airport people are needed. And when you get people doing pretty much everything from their home PC, how many people does an airline need behind the counters? And will people eventually pay to talk to them?