> Well, IE9 doesn't run on Windows XP, so it would have been hard to make a dependency specifically on that.

Doh! Forgot about that.

> Really the main reason why I'm switching over is to make for a more stable platform so that MoI's UI will run on the same engine on every installation, rather than depending on what version of IE is on any one particular Windows installation.

Sure, I get that. That will be a big win.

> Having an increase in script performance is more of a nice side benefit...

Well, I'm still hopeful about being able to do more with scripting in MoI, so WebKit/nitro sounds really exciting to me. Looking forward to trying this out sometime...