I thought that I'd chime in here. One of the things that I liked best about the IT when I reviewed it this time last year was the Opera browser. It was not just fast, but rendering of sites was very well done (and led to a good deal of bug reports to developers to fix their sites with correct code).
That being said, I am liking MicroB just a touch more because of the expanded features support. I do wish that it were more like the FF3 beta and load HTML lighting fast, but it does ok in that dept.
One thing that I have not see much a definitve answer on has been the use of browser extensions. It would seem to me that on such a device that the use of extensions and widgets would be really good. But other than a few GreaseMonkey scripts, I do not see any. If that area of things could pic up (along with the rendering performance), I'd be happier with it.