“When I get sent a PDF, sometimes I just want to view it — I don’t always need to download and save it right then. So starting today, you’ll see a new “View” link next to PDF attachments you get in Gmail.” – Item in Gmail blog.
The e-book angle: Don’t forget the usefulness of Google Docs, too, for situations where you lack the usual PDF reader.
Related: Google Dictionary, available in Chinese, English, German, French and other major languages.
There is a firefox extention that does the same thing for PDFs on any page.
There us also http://www.scribd.com/ whith an interface for PDF’s.
It’s needless to say that it dont work with any sort of access prevention scheme.
In general all the tools and thechnologies exist to move books on to the web, but noone in the e-book publishing industry is planning to do it.