Ballmer on webcast from New Orleans.

Microsoft has been purposefully quiet about Google's plans for a new PC operating system -- until now. Answering questions at the Microsoft Worldwide Partner Conference in New Orleans this morning, Microsoft CEO Steve Ballmer said Google's strategy with its Chrome OS isn't clear to him, particularly because its Android mobile-phone operating system is being expanded to netbooks.

Ballmer started by noting that he wanted to be respectful, but he added that it's not entirely clear yet what Chrome will be, and on top of that, it isn't scheduled to be outuntil next year.

"The last time I checked you don't need two client operating systems," Ballmer contnued, via webcast. "We tried it before. Windows 95 and Windows NT. It's good to have one. So I can't -- I don't really know what's up at Google.

He added, "Let me comment, though, about our own situation. What we really do understand is that the model fo the future brings together the best of today's rich client Windows-style applications and some of the things that people consider the best of the web. ... So as we talk about where we're going, we don't need a new operating system. What we need to do is evolve Windows, Windows applications, IE, the way IE works in totality with Windows, and how we build applications like Office, like the stuff we showed here, and we need to make sure we can bring our customers and partners with us."

Google addressed the two-OS issue in its post introducing Chrome OS.

Google Chrome OS is a new project, separate from Android. Android was designed from the beginning to work across a variety of devices from phones to set-top boxes to netbooks. Google Chrome OS is being created for people who spend most of their time on the web, and is being designed to power computers ranging from small netbooks to full-size desktop systems. While there are areas where Google Chrome OS and Android overlap, we believe choice will drive innovation for the benefit of everyone, including Google.

Google has said the new Web-oriented Chrome operating system will be released in the second half of next year, initially targeted to netbook computers, and the company has lined up some major PC vendors among the initial industry partners working on the initiative.