We're currently working on this for Feedbooks. Right now we're beta testing a simple RSS feed to PDF, mostly working on improving the support for the HTML to LaTeX parser.
We'll offer an easy way to create e-newspapers with multiple RSS feeds + elements such as weather forecast, sudoku etc...
We're also working on a small app to autosynchronize those newspapers on both the iLiad and the PRS-500.
If you're looking for a way to pull content from a website, you should try Dapper:
http://www.dapper.net
You can easily extract content from any website using Dapper, create RSS feeds out of it and then use these feeds as elements for your newspaper.