Keep it moving… Tumblr promotional post from Microsoft pushing their Nokia Lumia Windows Phone (and the new Windows Phone Tumblr site). Good to demonstrate how Tumblr is becoming more of a medium to which big brands are devoting marketing resources. Nothing extraordinary about the creative here, just a fundamentally solid use of the social media platform. Kudos though for new bright and simple branding (beating Apple to the punch). We’ll say it again, but we really dig the shift to flat graphics. Get on board world, it’s a comin’…