Is it just me or is this blog post not clear on what the definition of "business app" is? If it's for internal use, fine, whatever. If it's for enterprise application for millions of users, build the backend in C#/Java/Python/Ruby/Erlang/yourlanguagehere and build the frontend in something crossplatform like HTML/JS or Flash/Air. If you plan developing apps as a business, look at the SaaS/SaaP/cloud model.