This is exciting news. I have been hooked with Mendeley as my primary referencing manager ever since it was recommended. I really like the Mendeley Desktop. The new version has better feature of annotation which I like very much.
Watch this latest video. It summaries well how Mendeley works.
Keep up the good work, Mendeley. I will continue to support you. Oh, by the way, please come up with better version for iPhone/iPad where I can easily view my annotation. Thank you.