An Apollo upgrade for Windows Phone users appears in limbo after confused reports to its availability emerged.

At first the signs were good, with a Microsoft developer saying that all existing Windows Phones would be able to upgrade to the “next major version” of the platform. 

However, Microsoft has since been quick to put the dampeners on, with a source claiming that this will categorically not be the case.

If there does indeed prove to be no upgrade from Windows Phone Mango to Apollo, it means the likes of the recently unveiled Nokia Lumia 900 will soon be running on an inferior operating system to future Windows Phone devices.

So far it’s all just speculation, with Microsoft’s only official stance on the will it, won’t it upgrade fiasco concerning app compatibility.

"We have stated publicly that all apps in our Marketplace today will run on the next version of Windows Phone. Beyond that, we have nothing to share about future releases," it says.

If no Apollo upgrade is forthcoming, we can only presume this is due to the OS being too advanced for existing Windows Phone devices.

Exciting sure, but that’s unlikely to be little comfort to customers who have just shelled out on a Nokia Lumia 900.

Do you think Microsoft will make an Apollo upgrade available? Let us know your thoughts.