Yes, IE10 has a lot of cool HTML5 features and even some interesting proprietary features. I also suspect that the performance will be a lot better than IE9 on the phone, so stay tuned.
More information has come out of the conference, and the official info is that they will support HTML5 apps in some kind of browser control, but not as tight as the HTML5 apps in (big) Windows 8. Everyone seems focused on the ability to write C/C++ apps on the phone using the refactored NT kernel, and many are confused about what aspects of XAML/.NET will be supported.
But there will be HTML5 support and maybe we can wedge Construct in there somehow.
Maybe a tempest in a teacup since the market share for Windows Phone is pretty small now and may not do well since none of the Windows 7 phones can be upgraded to Windows 8. I guess I'll chuck my Windows 7 phone in the same pile as my Blackberry, Palm, Windows CE, and other dead technologies. <img src="smileys/smiley36.gif" border="0" align="middle" />