From Phil Schiller, Apple’s senior vice president of Worldwide Marketing on WWDC 2013:
Our developers have had the most prolific and profitable year ever, and we’re excited to show them the latest advances in software technologies and developer tools to help them create innovative new apps. We can’t wait to get new versions of iOS and OS X into their hands at WWDC.
Schiller intentionally mentioning iOS and OS X seems like mis-direction. I’m fully expecting Apple TV OS (iTV OS? iOS?) announced in June.