I've been using IE on Xbox for several weeks and it works pretty well. Of course there's no Flash so it's similar to surfing on an iPad etc.... It works even better if you have the keyboard attachment for your controller. Surfing the web in 60" of HD screen space is pretty cool.

Downside is that now it's even harder to get time on the Xbox with gaming, watching videos, and now web surfing. Might have to get an Xbox and TV for everyone in the house... j/k