Of course, for people who have never used PDAs and never will, and only use paper and their desktop / laptop PC, it will be considered useless. I do not know how large the PDA / handheld computer crowd is. Maybe it is not that big, maybe it is. To say that it is an example of “we can do it, therefor we should” is negating the fact that we live in a digital age. It is negating the fact that we use Scrivener on the Mac.
There is a generation that has grown up in the digital age, and use the digital every minute in their lives. And then there is also the older crowd who have embraced the digital as a great tool for doing what they did before, but better. Or else, we would all still be using typing machines - some great writers still do, of course, and many still use the pen! But there is such a thing as progress. People use their mobile phones and iPods for many things, because that is what they have in their pocket. It is their address book, their notepad, and more. Paper is only used when they have to print out something.
With Apple moving their iPods to the iPod touch platform, there will be a proliferation of handheld computers in people’s pocket. It is what people use for music in the first place, but soon they will discover other uses. Students will most certainly use it for many things. And then there is the crowd of longtime Mac users who have dreamed about a great Apple PDA for a long time, and now it is finally here!
How marginal the use of ScrivNote will be, cannot easily be guessed, not even from reading this thread. All I can say that if there will not be a Scrivnote, it is not the end of the world. But, I will still use other apps for writing on my iPod touch, because I am part of the crowd who has embraced the digital. Scrivnote will just make it easier for text to be imported into Scrivener, that is all.