BookViseris your typical reading app, and it supports Epub and FB2. There's no DRM support, but the app lets you search for a definition in Google. Sharing options include Twitter, Facebook, and email, and you can also copy text and paste it elsewhere. Other features include bookmarks and search, and you can also adjust the font size, line spacing, and font type.
While this app doesn't support DRM, it does offer an immediate choice of several ebookstores and free ebook sites, including Feedbooks, Smashwords, Project Gutenberg, and AllRomance. You can find the app in the Windows Store.
Has anyone tried Bookviser yet? I don't have Windows 8, so I cannot, but even if I could I think the fuax page turns would be enough to push me away.