It's shaping up to be a very big week for Microsoft as it looks to do battle with Apple's iPhone. The first phones with Windows Mobile 6.5 -- the new mobile operating system from Microsoft -- were announced today. AT&T and HTC just moments ago formally announced the HTC Tilt and HTC Pure. Both phones include a touch screen interface and will eventually have access to the Windows Marketplace.

We are looking for more announcements as Microsoft revs up the marketing engines for Windows Mobile 6.5, a serious attempt to recapture some of the market share losses to the iPhone.

Here are the nitty gritty details on the two phones, with the Tilt geared more to professional users and the Pure more of a consumer offering.

HTC Tilt

Cost: $299 (after rebates)

Screen: High resolution 3.6 inch screen

Keyboard: Slide out full QWERTY keyboard.

Audio: Speakerphone includes dual speakers and dual microphones with advanced noise cancellation. (Conference calling can be activated by turning over the device).

HTC Pure

Cost: $149 (after rebates)

Screen: 3.2 inch WVGA screen

Camera: 5 megapixel autofocus camera with video capture.

"The HTC Tilt 2 and HTC PURE are not only powerhouse devices, they also provide a natural simplicity in the way we communicate with the people in our lives whether through voice, text or email," said Jason Mackenzie, vice president of Bellevue-based HTC America. "Our desire is to put people at the center of every mobile experience, and we are pleased to work with AT&T, who shares this common vision."

AT&T, which is the exclusive carrier for the iPhone, said it was one of the first carriers in the U.S. to support Windows Mobile 6.5.

In a statement, AT&T's Michael Woodward said the HTC Tilt 2 and HTC Pure "will lead our Windows phone lineup into 2010."