Though I'm rather biased, I think it would be very cool to have Web Routines in Microsoft Internet Explorer 8.
It would be a useful feature for the users, and useful vehicle for advancing Microsoft's on-line advertising aspirations.
http://aadhoc.blogspot.com/2008/03/web-routines.html
I have gotten some positive feedback from Microsoft employees.
It could work well in Google's web-based offerings too.