First and foremost, you now have 4 major ebookstores with a browser based reading app, and they all work on Chrome. I don't like the browser reading apps because the Kobo, Kindle, et al apps for Windows are better, but it is great to know that you have the option.
- Google Play Books
But that's not all you can do. There's a bunch of PDF tools for Chrome, including ones which will let you read, edit, create, and merge PDFs.
There are the RSS feed readers, a couple Google News readers, and there are apps for Instapaper, Readability, and Pocket. As for comics, I can see apps for AveComics , Marvel, and Graphicly.
The reading community Wattpad has a Chrome app, and so does its less well known competition BookieJar. And of course there are apps that can play audiobooks.
That's not a very broad selection when compared to Windows, OSX, or Android, but it's a lot better than it was only 8 months ago.