I think Google's business plan is a key to how and why they are a successful internet entity and have been for some time now.
Google knows that it's power is the sheer numbers of 'users' that use their products, most for free. I don't think Google would want to jeopardize the number of users they currently retain by beginning to charge for services, but they already own their own, very popular, internet ad/revenue sharing service and, obviously, could implement advertising into any or all of their products, but I really don't see that being forced onto people either.
I think, for the most part, Google tries to keep their products as free as possible. I am sure Google sees an opportunity to make money right now, but will give up the consumer dollar right now in exchange for development rights money down the line. Especially with the economy the way it is, Google will certainly attract those that want nice, clean and free services.
I've also advocating (with no authority or credentials what-so-ever) that internet companies with, literally, no assets other than some computers, need to tread lightly on 'fees'. Because, as we have seen more than once now, how a large "multi-million dollar" internet company become virtually worthless in zero time. If your companies "power" is the amount of users you have, then keeping those users should be pandamount and charging fees would be the first step towards losing that "power".
Again, with portability and internet streaming becoming even more prevalent (
more mobile devices now use wifi more than computers) I think Google is just getting a fast start into a realm that is growing at an extremely fast rate and consumers are craving more.