Whether you like it or not, metro isn't going anywhere.
Maybe not, but many of their customers are, I've seen countless customers opt for a $1500 mac over a $700 windows 8 machine because it had windows 8 on it.
I've seen many others bounce back and forth from the apple side of the store to the windows side looking for options, most of those who end up buying a windows 8 machine are very reluctant to make the purchase and many of those who do buy one end up returning it.
I highly doubt mac will ever overtake the windows 8 machines purely out of the cost difference but just seeing customer reactions in person every single day it's easy to see they are not at all happy with the windows 8 machines that are out there and are desperately looking for options.
This whole hatred and contempt attitude toward their desktop customers is already costing them badly, their image has reached new lows and getting lower every day and it serves them right, the fact that the windows 8 adoption rate is far lower than Vista was is already proof of that.