I still have a logitech m-bb48. It has a ball. It has two buttons, and it has a scroll wheel you can feel scrolling. It cost $20 in the 90s. I'm not competitive in MLG or anything so I really just don't see any difference at all.
There are things I can justify spending money on for my computer, and there are things where there is simply no reason to spend it. Microsoft's new, expensive, gimmicky mouse can be thrown on the heap of other expensive, gimmicky mice that only the most foolish of "enthusiasts" will throw their dollars at to find that the gimmick isn't that great and the expense was too great.
Thats their sales pitch? portability? LOL what the heck? They gotta do better than that. My laptop mouse is already portable as it is, what will make me buy this thing? Right now I dont have a reason to buy it.