MacRumors.com

TUAW reports that they have heard that Apple will be seeding developers with an early build of Mac OS X 10.6 at this year's WWDC. This news comes in the midst of reports that Apple is preparing for 10.5.4 -- an ongoing maintenance release of Mac OS X 10.5 (Leopard).

TUAW also believes that Mac OS X 10.6 will ship in January 2009, about 15 months after Leopard's initial release in October 2007. This actually corresponds to Steve Jobs' comments to the New York Times regarding major Mac OS X releases:

“I’m quite pleased with the pace of new operating systems every 12 to 18 months for the foreseeable future,” he said. “We’ve put out major releases on the average of one a year, and it’s given us the ability to polish and polish and improve and improve.”

The blog also revives rumors that Mac OS X 10.6 will drop PowerPC support and become Intel-only.

While we can't vouch for the January timeframe, MacRumors had also heard that Mac OS X 10.6 would be making a debut at WWDC. We were uncertain, however, how public a release it would be: whether it would be seeded to a limited number of developers or if it would be a more central focus in Jobs' keynote address. According to this report, however, Apple will not be introducing any new significant features in 10.6, instead focusing on "stability and security."

References to Mac OS X 10.6 were recently found within the iPhone SDK installer. Mac OS X 10.5.3 (Leopard) is the current public version of Mac OS X.