Apple prepares to let the cat out of the bag at this year’s WWDC, rumors have it. Of course, we’re talking about the brand new Mac OS X 10.6, which TUAW says could start shipping by January 2009, if everything goes according to plan.

The Apple Worldwide Developers Conference will take place in San Francisco on June 9-13, and is expected to bring some groundbreaking news on the Mac OS X Leopard.

What’s new about Leopard? Well, it’s not going to be a big difference compared with the previous OS in terms of features, but will focus primarily on stability and security, the unofficial Apple blog also reported.

Another thing Apple is said to do is create an Intel-only Mac OS X, rather than make it compatible with PowerPCs. That decision, if accurate, will probably create quite a lot of talking at the WWCD, if Apple decides to make the announcement there.

The code-name for the new Mac OS X could be “Snow Leopard,” but again this is just a rumor, and we need to wait for the WWCD to see if it’s true.

There are a lot of rumors going on about the WWCD, and for now, the one that seems to be closer to reality is the Apple 3G iPhone. None of the rumors however has been confirmed, as Apple always likes to keep a little mystery before any event.