They'd add visual appeal and might add functionality as well. I can tell from a screenshot which page on my site is being referenced more quickly than I can scan the URL.
A visual way to browse popularity by screenshots could be interesting. http://pttrns.com is a site about design patterns, but the overall style (big pictures, minimal text) fits with Microsoft's "modern" aesthetic.
- Default sorting options could be useful.
For example, "most popular" could aggregate the Facebook and Twitter likes and then display the URLs in order of most liked to least liked.
- Visualization of changes over time.
Microsoft's finance app shows one minimal, tile-y concept for a way to display increases and decreases over time.