Paul Thurrott has a good article explaining the lack luster sales of Windows 8 over the holidays, primarily being netbooks have driven the price of PCs down over the years making it harder for higher priced touch screen devices to sell.
I think that may be part of the reason, but a bigger reason is Microsoft owns the enterprise and the enterprise did not roll out Windows 8.
Too many IT managers I know will not roll out Windows 8 due to the major change in the user experience that the new OS provides. As an IT manager, they do not want their help desks to be inundated with calls from their users on how to do some of the most simplest of tasks associated with the OS. With Microsoft leaving out a simple way of defaulting to the desktop, they distanced the enterprise.
This was not the case with Windows 7. The enterprise willingly embraced Windows 7 as it was perceived to be a big improvement over Vista (which many organizations did not roll out due to the many complaints of it being a buggy OS).
Microsoft loves touts a phrase called the "consumerism of IT", where the consumer is used to using technology like iPads, phones, etc at home and want to use the same technology at work. But, it works in the reverse, as I would call it the "enterpriseism of the consumer", if that makes any sense. As an organization places IT requirements on their users, like the OS to use, computer hardware, etc, it in turn influences the consumer in the purchases they make for home use. As the enterprise goes, so does the consumer. Since the enterprise went Windows 7, so did the consumer and sales were good. Since the enterprise didn't embrace Windows 8, neither did the consumer.
Once the enterprise sees value in upgrading to Windows 8 (or probably Windows 10, since version 3 is the golden rule in the enterprise world, and that would be version 3 of the Metro UI), then the consumer will be willing to move over to something they're used to and sales will follow.
I could be totally off here, but knowing corporate IT, help desks, and the rule of version 3, it's what I see. And don't expect Surface Pro to jump off the shelves, besides many IT organizations have hardware relationships in place with companies like Dell, HP, CDW, software is something entirely different.
What are your thoughts?