You should try running NetScape 3 on modern hardware... It flies.

It's easy to optimize a subset when you can define the subset to exclude everything you can't make fast...

Maybe, for certain definitions of "outperform". I can't watch the video right now (at work), but no HTML5 or modern JavaScript engine means that it'll fall behind the web very quickly unless Microsoft provides updates.

Personally, I doubt that MS will provide those updates. The reason they keep IE6 outdated is because large companies want it that way; that can't handle epic change or their apps will break. If MS is marketing this phone to businesses, you can bet that the browser won't change much.

MS isn't marketing the phone to businesses. WP7 isn't shipping with support for 'enterprise' features like domain enrollment (though it does support Exchange, to some degree).

Also, let's say that companies start buying WP7 phones for employees, and that they pay to build a mobile-friendly version of some internal webapp. If you were designing/coding a site today, and knew you didn't have to support IE6, you most likely code it in a fairly standards-compliant way so that it didn't break when browsers were upgraded; a lot of companies are stuck on IE6 because they didn't code their sites like that.

The comparisons are about load/render speed of normal websites (like Engadget) and scrolling/zooming – not really about HTML5 or Javascript performance at all.

I wouldn’t say that anyone outperforms anyone else in that video – all three phones seem to be doing those tasks equally well (save for choppiness on Android).

They keep IE6 outdated? I thought they released IE7, IE8 and now IE9 after that.

I don't think companies are going to develop for just IE mobile like they did for IE6. And how exactly does adding support for HTML5 break the HTML for older web apps?

Their strategy relies on fragmenting the browser space. So, they have various subsets of various versions of HTML, each supported by a different browser on different platforms. All that so you can't deliver web applications easily.

Companies who swallowed their poison pill in the early 2000's and built their intranets dependent on IE 6 are feeling the pain now, having to deploy intrusive security measures that don't really secure anything while shouldering the cost of "upgrading" the apps to browsers that run on the OS they want to deploy.