We will be supporting OS X 10.10. As with previous major updates to Mac OS X, we are working with the developer previews and preparing updates where needed.
For those thinking of upgrading to Mac OS X 10.10 immediately, we recommend waiting. If you use your Mac professionally, your best option is to wait a month or two after the official launch before upgrading. This extra time will allow hidden problems to come to the fore and to ensure all your software is truly ready.
We will keep you informed as our OS X 10.10 updates are launched.