This was confirmed by Microsoft at its BUILD conference last week.
Ted Dworkin, lead director for the Windows Store development team, spilled the beans at a BUILD session:
"We will be the only store for distribution of Metro-style apps."
The reason, according to Dworkin, is security:
"We will examine every application that will be submitted to us, we will run a virus check and a malware check on every application."
But Microsoft has an ulterior motive - cash. A 30% cut of all sales, a norm that Apple has established with its own App Store. Microsoft isn't talking specifics yet, but Windows blogger Long Zheng uncovered Microsoft's plans in an MSDN document (which has since been changed to remove the reference to the revenue split):
Following industry norms, developers pay a nominal yearly fee to upload apps to the Store, and receive 70% of the gross income from those apps (for paid apps and in-app purchases that use the default commerce engine). With this basic cost structure, the Store has many benefits...
The document also made reference to an activation limit for apps similar to that offered by Apple:
Any customer who pays for an app can install and use that app on up to 5 Windows Developer Preview devices, so that the app can engage that customer across a range of form factors.
There will be a free listing service for traditional non-Metro apps, as outlined by Antoine LeBlond, the VP of the Web services group:
We're giving these Win32 apps a free listing service and exposing them to all of the hundreds of millions of Windows users.
Also mentioned are trial versions of apps and in-app purchasing.
Is any of this fixed in stone? Don't bank on it. Here's what's right at the top of the document:
[This documentation is preliminary and is subject to change.]
While I think that Microsoft might make some cosmetic changes to how its app store works, I don't expect the model to be that different to Apple's iOS or Mac App Store. Devs will have to pay up to to get apps in the store, and there will be a revenue split.
One way that Microsoft could encourage devs to puts apps in the store is drop the revenue split on Metro apps for a period of time and allow devs to collect 100% of the revenue.