Our own preview version of Office 2013 shows a expiration date of January 20th when we checked out Microsoft Account info.
Some reports, such as the one we spotted at McAkins Online, said that the preview build would be expiring today, January 16th. For the past few days, we have heard that some people who have downloaded and used the free Office 2013 preview version via Office 365 have been seeing that their trial would be expiring very soon.
