Microsoft is holding a developers event today to go over the future of its Windows Phone mobile operating system.

That means we'll finally get a look at Apollo, AKA Windows Phone 8, the next major version of Windows Phone.

Microsoft has done a good job at keeping Apollo a secret, so we don't know too much about it. What we do know is that Apollo is based on different software that likely won't be compatible with current phones like Nokia's flagship Lumia 900.

Microsoft won't say whether or not that's true, but we're guessing the lack of denial means current Windows Phone owners will be stuck on the old version forever.

Luckily, Microsoft has already said apps on the current version of the operating system, called Windows Phone 7, will run just fine on Apollo. That's good for developers since they won't need to rewrite their apps to work on the new version of Windows Phone.

Microsoft's announcement starts a noon Eastern today. We'll have live coverage right here.

Don't Miss: Photos of Microsoft's Surface tablet >

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