In all seriousness, I'm predicting that the future of the web is going to be heavily reliant on SVG-generating programs and a new generation of WYSIWYG web editors, along the lines of Adobe Flash. It's quite possible that people will stop writing HTML directly—check out the Scheme dialect used in http://www.chris-granger.com/2012/04/12/light-table---a-new-ide-concept/
But seriously, HTML5 is a pain in the ass to fully take advantage of. If/when Adobe ditches Flash, we're going to see a lot of new design tools intended to replace it with SVG animations.
And last time I checked, people were still searching for a good unifying language so they could avoid writing HTML and JS directly. There are a lot of these, and they're all recent efforts.
>>8
People will always want to cram more crap into the browser. More games these days than animation, but it's pretty much certain that there will always be change and upward-building.