Being virtually the same core as W7,why the need for such a tool for W8?
M$ can talk up W8 all it can, it's a no-brainer for W7 users to stick with the best modern OS there is,W7.
To state that W8 will run quicker on old systems,is like putting it into the same class as Linux, to run on older hardware.
I'm certain that in these straghtened times,people value their money more than they ever did & that exaltations to spend their hard-earned money on something that they already have,will fall on deaf ears.
Ballmer needs to get out of the office a bit more,if something is good,it will sell like hot cakes,as it appears that 'Surface' is one of those 'hot cakes'.
Unfortunately,M$ have always been hit-miss with their OS updates,with the PC market in the doldrums,until some new technology appears,that allows super-computing speeds,at low energy & system purchase cost that's where it will stay.