The kernel of Microsoft's mobile operating system may not have changed much, but a great deal of rethinking has been applied to making one of the world's more prevalent smartphone systems behave more sensibly, like a phone.

At a keynote address this morning at the CTIA Wireless convention in Las Vegas, Microsoft lifted the covers off of Windows Mobile 6.1, a widely anticipated refresh -- and in some cases, perhaps a correction -- to its mobile operating environment. Touch-screen operation is being added to a significant number of features beyond its home screen, which premiered in WM6 to mixed reviews and which for WM6.1 will get a highly anticipated overhaul.

Helping to emphasize the company's point, the new home screen is being called the "sliding panel." For non-touch screen users, the metaphor may be a little tricky to embrace at first: Essentially, the system's "today" screen comes with small icons beneath a much larger digital clock, representing missed calls, voice messages, text messages, and e-mails. To move between those categories, you navigate left and right; the "panels" slide over each other like magnifying glasses, revealing the most recent entry in their respective lists.

Under the new system, items in lists are shown not as long tables but as single items on individual panels. A separate "Getting Started" panel shows a similar list of tasks a user may perform to get a service under way, such as pairing a Bluetooth device. The "one-at-a-time" approach is new to Microsoft, which appears to be moving away from the notion of making Windows Mobile look like Windows, in favor of focusing the user's attention on single items...and reducing screen clutter in the process.

Applications and features of the phone may be chosen by sliding up and down (that's how you find Getting Started), and items belonging to the currently chosen feature are browsed by sliding left and right. As you might imagine, it wouldn't take as sophisticated a touch-screen system as the one on Apple's iPhone to accept these instructions; they're basically series of vertical and horizontal strokes, or perhaps "scratches." Microsoft may have developed this system to address manufacturers with less capable phones and narrower means of control.

"More convenience, less clicking, so you can get back to your life," states the narrator of an introductory video unveiled today.

Another long-sought enhancement has been the combination of multiple text message threads onto a single screen. Quite obviously, this enables multi-party chat; and ever since developers were told to expect a spring launch date for WM6.1, multithreaded texting has been among their top demands, if not the one at the top of their list.

AT&T Wireless, Sprint, Alltel, and T-Mobile were the carriers announcing Windows Mobile 6.1 support at CTIA today. Among the major manufacturers showing off WM6.1 on their new and existing models today were Samsung with its BlackJack II, Motorola with its Q 9c and Q 9h, and HTC with the promise of a new Touch Dual model for US customers.