As you can read on the Official Office Sustained Enginering blog SharePoint 2013 SP1 has been released (amoung other Office products SP1s)
What's new in SP1?
SP1 provides fixes to improve general stability, functionality, and security in Office, SharePoint Server, and related products. Among the functionality improvements and changes are the following:
- Compatibility fixes for Windows 8.1 and Internet Explorer 11.
- Better support for modern hardware, such as high DPI devices and the precision touchpad.
- New apps for Office capabilities and APIs for developers.
- Power Map for Excel, a 3D visualization tool for mapping, exploring, and interacting with geographical and temporal data in Excel, is now available to Office 365 ProPlus subscription customers. You can learn more about Power Map general availability on the Power BI Blog.
- Improvements to the Click-to-Run virtualization technology that installs and updates Office 365 desktop applications.
- SkyDrive Pro is now OneDrive for Business.
How to download them?
You can download them from http://www.microsoft.com/en-us/download/default.aspx or via Microsoft Update and the Windows Server Update Services (WSUS) catalog. After a 30-day period, SP1 will begin releasing as an automatic update through Microsoft Update.
For Office 365 they will be installed in the next regular update.
In theory it includes all PUs, Security updates and CUs until January 2014 (So FEB 2014 CU is not included)
The kbs for them are
Project Server (IT'S NEEDED TO INSTALL BEFORE SPS 2013 SP1 BECAUSE IS NOT INCLUDED)
Office Web Apps
BTW, I'll create an update guide as I did with SPS 2010 SP1 and SP2 to clarify the steps of installing the SP1.
Héctor Calvarro Martín. SharePoint Dev/Core. EMEA Premier Field Engineer.