Ok. Now its out of preview and now if one visits hotmail. They are clearly suggesting people to upgrade to outlook. But,
Outlook Blog - Upgrade from Hotmail to Outlook.com
Important: Don't sign-up for a new account; just sign-in with your existing Hotmail account. You don't need to change your address to use Outlook; in fact, if you sign-up for a new address, there is no way to combine or merge that new account with your old account.
Also
All your data and settings just work
When you upgrade to Outlook.com from Hotmail, you get the new Outlook.com service, and you keep everything about your account intact:
Your email address continues to work - no need to change it
You will continue to sign-in with your @hotmail.com using the same password
All your devices will continue to work, including your phone and the Outlook client with the Outlook Connector
You retain all of your contacts - no extra steps to take
You retain all of your folders, categories, flagged messages, rules, etc.
Your signature and vacation reply come with you
Your settings for things such as Reading Pane and Arrange By Conversation stay the same