This makes perfect sense, at least from my anecdotal experience: there are tons of people who want to develop for the App Store but don't want to spend thousands to buy a new computer running OSX to do it. At this point, a developer who doesn't have an Apple laptop isn't likely to get one, so there are few hardware sales to lose, but a lot to win by letting Windows-based developers make apps for iP*s.
So the Windows coders who balk at a several hundred dollar 'Apple tax' are going to instead shell out several hundred dollars for a VS2010 license?
Or is the theory that Microsoft would let a feature like this wind up in Express when their own tools to develop for Windows Mobile are only available in vs2010 licenses that cost more than a macbook and app store license combined?
EDIT: Which isn't to say that it won't or couldn't be plausible. But if it does happen, it will be all about enterprises: The sorts of places that wouldn't blink at the cost of a Mac, but would balk at having to train, staff and support a completely different toolchain and environment.
The mac mini is more than a reasonable machine for development. I use it for gaming, design work in CS4 and development, when I don't feel like using my laptop.
That would mean that the 'tax' is only $500, or cheaper if you get it refurbished.
A lot of the developers who would be working on small apps for the iPhone/iPad would probably qualify as small businesses for Microsoft's BizSpark program, which gives them free access to lots of tools including Visual Studio. You qualify as long as your business is real, less than 3 years old, and earning less than $1mm in revenue. Once you exceed that, you should be able to afford the licenses.
