I think it would be a nice feature and it wouldn't be too difficult to implement either. (just add a gutted version of IE)
I know I really enjoy being able to browse the PSblog, check something on wiki, or check the weather without having to get up *groan* and go to my laptop....
no seriously, it IS a very useful feature and I think it would be money well spent for MS.
Not trying to be a fanboy. Of course, it's hard when you own the best console eve... dang it