So on the Surface Review...

I'm not trying to be an apologist or anything, but from watching this Slashgear demo of Windows RT, the lag doesn't seem to be as much as Josh's wording makes it out to be (There is some, yes - Music and News are the two examples shown). It looks like it's really smooth, but not as fast as Windows Phone or iOS. Flash video and HTML5 video weren't shown.

Windows 8 RT on Surface RT walkthrough (via SlashGear)