Microsoft released the public beta for Office and SharePoint Server 2013.
You can find more information in the following articles:
- Office Customer Preview
- SharePoint, Exchange, Lync, Office Web Apps, Project, Visio, Office Professional 2013 Preview
- Microsoft unveils the new Office
- Webcast: Announcment from Steve Ballmer
Direct links for SharePoint 2013
- SharePoint Foundation 2013 Preview
- Microsoft SharePoint Server 2013 Preview
- IT Pro and Developer training materials
- Technet Material
- More Material