I moved to a Mac some years ago, and there is absolutely no product like this for Mac. iTunes, for all its hype, is awful and sucks when managing a large, meticulously tagged collection. For example, it tags things the way it wants, does not read tags properly (some albums labeled as artists), and little advanced features.
By the way, that "large, meticulously tagged collection" was organized using Media Center. In fact, iTunes screwed up my media files and copied them all over the place.
I am writing this on a Mac, and 2 years of using Songbird on Mac, I installed VMware Fusion just to use Media Center!
So yes, please develop a Media Center for Mac. People that say "develop for Linux" are in a minority - how many mainstream users use Linux? And while Android is a very decent OS, it is mostly smartphone and tablet based.
Will Media Center "replace" iTunes? No! People use it to sync their iPads and i-devices, plus many official account changes must be done through iTunes. It sucked when Microsoft integrated IE into Windows, and it sucks now that Apple is doing it with iTunes, but those are the rules made by the ones playing the game.
For one, I would love a Mac option. Sell it for half the price for a limited time and prepare yourself for some serious revenue.