You can write .NET WinRT apps and .NET desktop apps on all machines that run Windows 8.
What's the problem again? Also, apparently, nobody actually read exoteric's question?
well as of right now we can not use WinRt for a desktop app as the current version does not allow that. Right now have no idea what will happen in the next release of windows. So what can we say ? spin the magic 8 ball time ??
my thoughts: WinRT is a start of something that might be good *IF* MS finishes it and makes it possible to use it for non-metro apps. But we have to see what happens. .Net has great possibilities but is getting only half the use I thought it would. Xaml / WPF / Silverlight all have great abilities and half of that seems to be dumped ..... sorry Mr. C but MS has not impressed me of late.