I was just thinking, what about Chrome OS, HTML5, CSS3, jQuery/http://processingjs.org/ as a multitouch platform? Is it possible?
I personally believe yes. There are many examples of CSS3 based animations, transitions and other stuff (http://robertnyman.com/2010/05/06/css3-animations/, http://robertnyman.com/css3/, http://www.webdesignerwall.com/trends/47-amazing-css3-animation-demos/) that can greatly create the ux of multitouch applications. HTML5 provides us with offline data, canvas, audio, video and many other usefull tags (http://html5.mattonik.sk/, http://html5demos.com/).
So I think it’s really possible to use this combination to create real multitouch application.
Of cource, there are many other things that might cause problems, like connecting external devices, but do we really need this in all cases?