Lenovo Yoga 13. This week the app was updated and it now allows me to add any RSS feed whether it's featured by Bing or not. Once you've added a feed by entering the URL for the feed, you can put it into a category in the app. It's important to note that you have to enter the feed URL not the site URL in order to add a subscription (it's kind of like the early days of Google Reader and I hope that Microsoft changes that in the future).
What I like about the Bing News app is the clean and full layout of articles as I browse through them. What I don't like is that in order to share a story or bookmark a story, I have to open the "charms" menu then select share then select the app through which I want to share the story. It's not difficult, but it adds one more step than I typically use in Feedly or Flipboard. Overall, it's not a bad app but I'm still more inclined to use Feedly's Chrome app when I want to browse through my RSS feeds on my Windows 8 computer.