Microsoft officials announced the completion of the Hotmail-Outlook.com transition on May 2. Microsoft officials added that they've migrated 150 petabyes of email over the past six weeks.
As part of the announcement, officials also said they are adding two new features to Outlook.com: SMTP Send, making it easier to send mail from different email addresses; and deeper SkyDrive integration.
Of the current 400 million, 125 million Outlook.com users are accessing their accounts from mobile devices, officials said.
To those Hotmail users who are struggling with the Outlook.com interface: I'd suggest you check out this video and frequently asked questions (FAQ) document. I've heard from many (many, many) of you that you can't find your calendar, contacts, etc. Hopefully this page will provide some help.