I have long thought that it would be nice to have a new Web-alternative based on XHTML. With XHTML you get a clean break from the legacy early HTML cruft and design errors as well as avoiding the corporate browser vendor designed HTML5/HTML Living “standard”. XHTML is essentially the last Web markup standard actually designed (and not rubber stamped) by the W3C and I think it is telling that even today Tim Berners-Lee’s own personal website uses XHTML.
Or May be even a new standard that compiles into HTML / CSS / JS. A standard that fits most uses cases and is simpler to implement.