Seems to me that Google is likely wanting to compete with paper.li, storify, plus Flipboard and other apps mentioned in the article. Mobile also looms large in Google's plans, and Flipboard doesn't run on Android.
Where Google wants a certain kind of content because this new app has been under development?
Not sure what a "certain kind" is here. I assume Google is trying to weed out a lot of material, which it considers to be either redundant or of low quality, that threatens otherwise to overwhelm its capacity. The only connection I see with Panda is that Google would hope that a rising tide will raise all boats... or at least all boats that have managed to stay afloat.