[casualviking]

You need a Mac to be able to build IOS apps. And to run the IOS simulator.

Announced today however, is the ability to remote the simulator to a Windows machine. That probably means you can just buy a mac mini and stick it in a closet, potentially sharing it between multiple devs.

[JonathonW]

You can't quite stick the Mac Mini in a closet and forget about it, because you'll still need to connect devices to it when it comes time to deploy to device-- the simulator isn't complete enough to be the only test environment you use.