The future of publishing is in doubt. Since Apple's iPad launch just over a week ago, an already heated debate has got hotter. The iPad is essentially a magazine-sized iPhone on which you can read news and books (and play games, and send emails, and watch films…) on a rich colour screen. As a reading device, it's still not up there with that old master of reading technology, the book, but it's a powerful force for change.

People have argued that the iPad's too large to carry around, but the key is in the (widely mocked) name: where people would have carried a note pad around (or a magazine or a book) they will now carry the iPad – holding within it any number of note pads and the potential to read any magazine or book under the sun.  

Portability seems to be key – after all, the record lost to the CD, which has lost to the mp3 – which may soon lose to the ultimate in portability, streamed music from the internet.

So if this change occurs, how are publishers going to make any money from digital content? Newspapers, after a decade-long experiment with free news content on the web during which revenues have fallen off a cliff, seem to be finally facing up to the fact that a business model relying on advertising revenue alone is doomed to fail.

Perhaps small payments for content is one answer. It's a route that Apple has gone down with iTunes. Will people be willing to make small payments for digital content? People are already doing so for iPhone apps, and the iPad's rich, book-sized screen is likely to prove even more seductive.

It's all pretty unclear what publishing model's going to win out. All parties are pretty jumpy at the moment, as last week's skirmish between Macmillan and Amazon shows (Amazon petulantly stopped selling all Macmillan titles for a short time in an ebook pricing dispute). As Henry Porter pointed out in an article yesterday, the people that are being forgotten in this fight for survival are the ones that the publishing industry is totally reliant on – the authors.

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