You should take this with the requisite grain of salt, because it's not all that groundbreaking. AppleInsider notes that several references to Apple computers running OS X 10.9 have appeared on its server logs, suggesting that someone visited the site while using an unreleased version of Apple's operating system. True, this type of data can be faked, and it's not much of a surprise to hear that Apple's working on a new version of OS X anyway. Of course Apple will update OS X at some point.
But at the same time, server log references like this are often our first indication that something new is on the way, so you can at least store in the back of your mind that a reference to OS X 10.9 may have been spotted in the wild. Feel free to use that thought to fuel excitement through the long winter months.
What should we do while waiting for more official information? Why, figure out what Apple should name the new version, of course.