IMO the greatest change would not be in tcp/ip and below, but in http and up. If you had no knowledge of the current web, and I would pitch you html, css and js, you'd probably think it was a bad idea. Why would you use interpreted scripts over binaries if speed is mission critical. First you encapsulate your data in a markup language only to be parsed/converted back by the receiver, ridiculous. It also lacks semantics to make dynamic web applications readable for machines, not to mention the XSS vulnerability in the markup language that would make server side application unnecessarily complex. What a weak proposal, would never work.