Although I've left active HyperCard development for several years now, if HyperCard were to make some sort of modern return, I jump at the opportunity to build applications with it. There are many things I was working on in the 1990s that I would like to re-invent, if only I could distribute them over the internet and be able to have clients run the projects in their browser via a HyperCard plugin.
There has been a HyperCard plugin in the past, but we would need to market it, along with an upgraded version of the HyperCard suite itself. Color would have to be native-- none of the afterthought color tools of old. At least that, for God's sake! Not to mention other features.
I miss HyperTalk and the entire HyperCard model, the programming environment, extensibility, debugging tools, etc. It was the best, indeed.