According to a report by The Verge, Microsoft is planning to abandon their Microsoft Points System, which has been used primarily on their Xbox consoles.
Microsoft Points will be replaced by real money via a gift cards system, similar Apple's iTunes codes. These gift cards will allows users to use real-world currency, which then can then be used purchase virtual content. In addition, the sources said cash transactions through credit and debit cards will also be supported.
According to the source, this new system will officially be announced at E3, and will spread across the Windows Store, Windows Phone Store, and Xbox Live.
Source: The Verge