I think the ebook Market will exploded, just as the MP3 market has. People said the same thing when that started up.. DRM asside I have a business and a personal need to be able to view text formats e.g. PDF or html on the move without having to worry about a laptop.
RSS is now going very main stream an App which synched content from your favorite site for you to read on the subway would be great. Better yet if it has wifi or bluetooth you could in theory wake up and your morning paper has been delivered direct to your device.
my 2 cents