I would like to be able to see the feeds of more than one community at a time on a single landing page.
Certain communities are less active than others. I absolutely want to keep active in them but it can be a bit of a bummer to click through to a community you like and see no new content for a month. A hybrid feed would let me feel like I'm keeping tabs on these lesser-active communities without the extra clicks and let downs.
Chat room fast-navigation is already community-agnostic on the right-hand nav bar. Why not support an integrated question feed as well? :-)