Seems like they're giving people a reason to use their products, and then making a play to have an OAuth-level relationship with the users. Maybe they want visibility into how a user authorizes third-party apps (FB gets an awful lot of insight from FB connect!) or maybe they just want to solidify their user lock-in.

Either way, I can't imagine they justified the engineering work for massive redesign on seemingly not-profitable properties like Weather/Flickr without having a solid long-term plan for how to capitalize on that.

[1] http://www.engadget.com/2013/08/15/yahoo-weather-android-red... [2] http://blog.flickr.net/en/2013/05/20/a-better-brighter-flick... [3] http://techcrunch.com/2014/01/03/yahoo-sports-gets-ios-7-red...