Here's what you've missed:

• Yahoo Acquires Tumblr - Yahoo has officially announced the all-cash acquisition of blogging site Tumblr, picking up the six-year-old company for a cool $1.1 billion. (Promises "not to screw it up")
• Klout Now Lets You Share Your Expertise on Bing - Starting last week Klout is offering the opprtunity for topic influencers to increase their influence in an area by answering topic-related questions that Bing users often search for.
• Facebook Rolling Out Video Ads to News Feeds - Facebook will give brands four demongraphics to target with 15-second video ad spots.
• Microsoft announces the Xbox One - On Tuesday Microsoft announced its next-generation Xbox console, the Xbox One.