Frankly, this isn't going to get people all that jazzed, but
MG Siegler notes that a look at the Google Analytics for "Intel 10.9" on TechCrunch and his own site show increased activity. We did the same for Business Insider and you can see the results in this chart. (The reason there is a big drop is that it's early in the month.)
Apple's last operating system, Mountain Lion, was OSX 10.8. Presumably, 10.9 is the next operating system.
Last year Apple surprised everyone when it announced Mountain Lion without much fan fare. Instead of a big event it gave a preview to a select group of reporters. Those previews were published on February 16, 2012. It's been well over a year, so one would expect Apple to announce something soon.
Business Insider