1. SharePoint 2013 will include a new SharePoint Apps Marketplace.

2. New App Store Database Provider – App ‘package’ can be configured to use any back-end database that supports the new Database provider interfaces.

3. SharePoint Apps will support multi-tenant installations so that hosting providers can make available the same set of applications to multiple customers.

4. SharePoint 2013 gets a new Education module/option.
(Another FYI – Microsoft is also working on making its Office 365 for Education globally available this summer as the successor to Live@Edu. Microsoft plans three pricing/licensing plans for it, namely A2, A3 and A4, the first of them being free for both students and faculty.)

5. SharePoint 2013 and Exchange Server 15 are both getting additional built-in information-rights-management (IRM) document-protection functionality as part of the base products.

6. SharePoint Server 15 will also feature Rights Management Services (RMS) integration.

7. SharePoint 2013 supports OAuth.

8. MDS or Minimal Download Strategy (MDS allows websites to take much less bandwidth than with traditional technologies.)

9. Project Online: New Project site to manage lightweight projects.

10. Visio cloud service component.

11. SharePoint Duet: A cloud version of the Duet add-on Developed by SAP and Microsoft that allows SharePoint to integrate with SAP applications.

12. Support for viewing business intelligence content on Apple iPad devices.

13. New Versioning – Now you will be also able to version entire parts of SharePoint. An entire site for instance.

14. Improved Client Object Model – The Client Object Model is extended with Search. Also no need to add Form Digest control in your page you can include that in your ClientContext.