Just another thought that might help sony/other potential maker to make money on the faxing idea (please don't shoot me if you lose cash over it
):
Pick the first option (I am not saying it is the best option to take), and there should be a lot internet fax service providers out there, find and partner with the ones who wants to share revenue with you, that is, for every document faxed from this slate and through their app, they will pay you (that is, sony, and other potential slate makers) a fee, out of what ever the customers might paid them, since this device helped them to gain customers.