Windows Mobile 6.5 application screen.

The rumors were true: Microsoft this morning is unveiling a new mobile application store, a new mobile data-synchronization service, and an overhauled version of its Windows Mobile software -- which it won't be calling Windows Mobile anymore.

The company also is announcing a broader mobile partnership with giant LG Electronics, showing a new mobile version of Internet Explorer, integrating Windows Live Hotmail and Messenger more tightly into its mobile strategy, and following through on plans to connect Xbox Live to mobile phones. New phones are on the way to take advantage of the changes.

Those are expected to be the highlights as Microsoft CEO Steve Ballmer takes the stage this morning at the Mobile World Congress in Barcelona. Microsoft is trying to regain its footing after missing its mobile shipment goal last year, amid rising competition from the iPhone, BlackBerry, Nokia and others. Ballmer will be trying to show the mobile industry that the company can remain relevant. Read on for a rundown of the news.

Windows Mobile 6.5: The new version of the company's mobile operating system has been overhauled for touch-screen phones, with a home screen designed for scrolling vertically through menu items by flicking a finger, then delving deeper into specific menu items by scrolling horizontally. The approach will be familiar to users of Microsoft's Zune device, which uses a similar scrolling vertical and horizontal menu without a touch interface. The new OS is due to ship on phones starting in the second half of this year.

'Mobile' No More: Microsoft is dropping the "Mobile" from the Windows Mobile brand, instead marketing the notion of "Windows phones." Executives say they believe the "Mobile" has become redundant. The Windows Mobile name will still be used internally to refer to the operating system, and people checking the version number on their devices will still see it.

Windows Marketplace for Mobile: As expected, Microsoft is rolling out a new marketplace for mobile phones. This was known by the code name SkyMarket. The company will let people download apps from the phone itself, but it will also be possible to access them through any browser on any PC and load them that way. This will come out with the new OS this fall.

Application screen: A new Start menu, accessed by pressing the Start button, will provide access to applications, keeping the launch icons separate from the home screen. This differs from the iPhone, which displays everything up front. "Our philosophy for the home screen is it's not the dumping ground for apps," said Tim McDonough, Windows Mobile senior product manager.

My Phone: As announced previously, the company will be offering a new service called My Phone that lets people synchronize photos, appointments and other key data to a password-protected service, making them available for easy access online or as a backup if a phone is lost. A preliminary version of the service is now being made available by invitation.

LG Partnership: Mobile handset giant LG Electronics is planning to make Windows its primary smart phone operating system. According to a Microsoft news release, the move "will create a tenfold increase in the volume of Windows phones available from LG in 2009 and bring up to 26 new Windows phones to market in 2012 alone."

Windows Live Messenger and Hotmail: The company will now be shipping its mobile applications with the operating system by default, aiming for broader deployment of its key communications services on phones.

Internet Explorer: A new mobile version of Microsoft's browser seeks to replicate more closely the experience of browsing on a full computer. Among other things, the company has licensed Adobe's Flash Lite technology to display Flash-based pages on the phone.

Live Anywhere: This is Microsoft's strategy to connect PCs, phones and the Xbox 360. The company initially unveiled it in 2006, but the mobile part of the strategy has been slow in coming to market. Windows Mobile 6.5 is expected to let mobile phone users send messages to people playing games on Xbox Live, for example, realizing at least part of the original vision.

Coming up next: A Q&A with Microsoft mobile chief Andy Lees.