Using web technologies to create desktop applications

Recently, the pace at which web browsers improved and implemented new technologies (e.g. HTML5) seemed to have accellerated considerably. At the same time, the tools for developing web applications, like e.g. jQuery, or the myriads of web frameworks have also made web development much easier.

Are we now at a point were it makes sense to develop a pure single-user desktop application using web technologies? Assuming we can just install the latest browser together with our application, we don't have to worry about compatibility with older browsers.