Hi Mycroft, we're testing a notification system. The number represents the number of 'unread messages' you have. If you click your name or number, you will see a list of notifications that the system has selected as relevant to you (such as replies to blogs or forums you have commented on or posted in). Once you visit this screen, the messages are marked as 'read' and your counter will reset to zero. Right now, we are fighting some spammers, so the feed is fairly worthless, but we hope to have a patch rolled out soon. Thanks for hanging with us!