Microsoft Points may no longer be the only form of payment in Windows 8. According to Polygon's experience with Zune Marketplace on a final build of Windows 8, users can pay using actual money rather than being forced to use Microsoft's oft-maligned currency. In Windows 8 preview builds, Microsoft Points were the only form of payment. Now, they apparently aren't even the default.
A rumor surfaced earlier this year suggesting Microsoft Points are being phased out completely, including from the Xbox Live platform they launched on. Two months ago, real money options briefly showed up on the Xbox Marketplace, though Microsoft claimed they were an error. The change to Windows 8 may be the signal of further changes across Microsoft's platforms, but for now the space bucks live on Xbox Live to fight another day.