As of a few moments ago, Adobe released Lightroom 4.4. This is a full release, meaning that it is available directly from Adobe.com or as an update from within Lightroom.
It includes more raw file support for 25 more cameras including the Canon EOS 1D C and Nikon D7100, it includes bug fixes that in previous versions, an updated imaging algorithm for Fuji X-Trans cameras, and more.
Details of all updates can be seen here.
To update your current version of Lightroom, open a catalog and an update dialog should pop up. If not, you can force Lightroom to check for updates by going to Help > Check for Updates within Lightroom.