Adobe and Apple have worked closely together to test Adobe Creative Cloud applications for reliability, performance, and user experience when installed on Intel-based systems running Mac OS X Yosemite (version 10.10). The latest versions of all Adobe CC products are compatible. In addition to the current Photoshop CC release (2014.2), the Photoshop team has also tested Photoshop CC 2014 (2014.2), Photoshop CC (14.2.1), and CS6 (13.0.6; 13.1.2) for compatibility.
As with any new release of an operating system, there could be unexpected issues that arise that were not discovered during testing. If you encounter any issues, report them using the bug reporting form.