Lexalytics customer mBlast posted on their blog a great piece on the downfall of Klout. Put simply, popularity is out, influence is in, and influence requires context.
"I’ve said it before and I’ll say it again: you cannot determine influence without subject matter. You can’t get subject matter unless you break down an author’s posts and analyze them. You can’t just rely on Twitter or any one Social Media stream because everyone uses them independently and even differently. And finally, unless you can put this all together and see the person’s voice across all streams, you have completely disconnected data that not only doesn’t tell you much, but can possibly even lead you in the wrong direction concerning what a person thinks or talks about." -An Obituary for Popularity
Check it out here.