Redmond hasn't yet promised a release date for Mango, but it has started sending out invitations to a "VIP preview" of the operating system upgrade on May 24, according to WinRumors. Over the weekend, a new podcast (downloadable in MP3 format) detailed some of Windows Phone 7.5's features.

Despite its official-sounding name, the Windows Phone Dev Podcast is produced by third parties -- Ryan Lowdermilk, a software consultant for Arxis Technology, and Travis Lowdermilk, a web/database developer for the Kaweah Delta Health Care District. The duo's latest podcast included an interview with Brandon Watson (left), Microsoft Director of Developer Experience, which led to some confusion on the part of Engadget and other sources (which was reflected in an earlier version of this story as well).

While Watson used his appearance to promote Windows Phone 7, hewasn't the source of Windows Phone 7.5 information. (Indeed, he lattertweeted, "I didn't spill Mango-flavored beans as some blogs implied.") Instead, the Lowdermilks merely cited "the screens we were given" as the source of the news, adding that they strongly believe the images to be authentic.

Windows Phone 7.5's turn by turn navigation (left) and podcast support (right)
(Click either to enlarge)

Some of the new features in Windows Phone 7.5 highlighted by the Windows Phone Dev podcast will merely bring the Microsoft smartphone operating system into parity with what is already offered by Google's Android. For example, a turn-by-turn navigation feature (above left) will provide voice guidance while driving, plus maps that can always face north or rotate with the direction of travel. In addition, it's said, Windows Phone 7.5 will feature on-device podcast support (above right).

But, the screens suggest, Windows Phone 7.5 will also leverage Microsoft's TellMe voice recognition services to permit hands-free texting (note the "speak" icon in the image at left below). Additionally, it's said, the operating system will include new Bing Audio and Bing Vision services (below right).

Hands-free texting (left) and audio-visual search (right)
(Click either to enlarge)

Bing Audio search will apparently operate similarly to an existing third-party service, Shazam. Users will be able to hold their phones up to a radio or other device playing recorded music, at which point the search engine will attempt to identify it.

Meanwhile, Bing Vision will apparently be a search service that uses a phone's camera. It's said users will be able to scan barcodes, Microsoft Tags, QR codes, CDs, DVDs, and (via optical character recognition), even text.

Separately, additional Windows Phone 7.5 features were revealed by a developer posting as "Wonderow" on the Cnblogs.com website. Though quickly removed from that site, details were noted on Liveside.net by "danmaster," who also archived some of the images that Wonderow had posted.

Enhancements to the Office Hub (left) and task switching window (right)
Source: Liveside.net

According to Liveside.net, Windows Phone 7.5's Office hub will include integration with Microsoft's cloud-based SkyDrive, adding Word, Excel, and PowerPoint sync (above left). Meanwhile, the website adds, the operating system's People hub will now integrate Windows Live Messenger, so that users will be able to IM people on their contact list directly. It's also claimed the task switching window (above right) will show not only individual applications, but also each tab that's open in the included Internet Explorer 9 web browser.

Jonathan Angel can be followed at www.twitter.com/gadgetsense.

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