I always thought of that as prototyping not testing and it's a skill that seems to be less popular for the new self-proclaimed professionals- though it's always been easy enough in the ASP/scripting world too.

I think there's more prototyping going on than people want to admit.

This isn't directed towards you in any way - but with each passing year, I see more people who genuflect on one concept, but engage in a different and arguably conflicting concept. I see people clucking platitudes on Twitter about "XYZ" when I know for a fact otherwise. It's almost laughable. But I digress...

I build throw-away prototypes all the time, and am proud to admit it. If for no other reason, it helps me wrap my mind around topics.

And re: VS Lightswitch....I'll bet a fancy steak dinner (but no more) that a year after people start using it, it will be known best for building throw-away prototypes. I don't mean "throw-away" in a perjorative sense - those things have value in the process.