Windows Phone developers who want to add in-app purchases to their products can do so, but only on Windows Phone 8.
Guidelines recently posted by Microsoft confirmed that developers "can only add in-app products to Windows Phone 8 apps." This means that users and developers alike using will probably be out of luck.
App makers who want to take advantage of the new feature are advised to explain the "fundamentals" of the in-app product, such as alias, price, type, and languages. They also need to provide Microsoft with a name and image of the product and a description as appropriate.
The lack of support for Windows Phone 7.8 may be tied to the fact that Microsoft's wallet hub is slated to debut in Windows Phone 8. The new digital wallet will be used for in-app purchases, according to The Verge, suggesting that the wallet hub won't appear in 7.8.
Windows Phone 8 will, including higher screen resolutions, Near-Field Communication, multicore processors, and expandable memory. The OS also throws in a revamped start screen with new color schemes and resizable tiles.
Phones running the new OS are scheduled to pop up sometime this fall. Windows 7.5 users won't be able to upgrade to the new version but can bump up to Windows 7.8 to at least get a taste of the new start screen.
A Microsoft representative told CNET that the only thing the company has shared about the Windows Phone 7.8 update is that it will offer the Windows Phone 8 start screen. "There's nothing more we can share at this time," she added, "but stay tuned in the coming weeks and months."
Update, 8:45 a.m. PT: Adds response from Microsoft.