The Office 365 Import Service is in preview. Essentially, this service is used to move PST files to Office 365 mailboxes and/or to import data files to SharePoint Online. Customers use the preparation tool to get their content ready and then can choose to upload data over the network or, for large amounts of data, to copy it to hard drives and ship them to Microsoft.
The service is free at the moment but will turn into a chargeable Office 365 service later. See the announcement here: http://bit.ly/1LXn0EH or this TechNet article for more details: http://bit.ly/1MUooOi.