According to a tweet from the official Microsoft Office for Mac Twitter account, Office for Mac 2011 will be available in stores this holiday season.
Office for Mac 2011 will feature the new "Ribbon" interface effect, similar to the one in Office 2007 for Windows. Also new in Office for Mac 2011 is Outlook. Currently, the email client included in the Office for Mac suite is Microsoft Entourage, but Microsoft has decided to switch over to Outlook for the new version.
Screenshots of Office for Mac 2011 were leaked to Boy Genius Report earlier this month, showing a much cleaner user interface than previous versions.

