Lol, I would hope so considering it a brand new OS and pretty much every PC Manufacturer was required to buy it. Revenue, even wholesale revenue is revenue. However, I would expect MS was hoping for something more from a brand new OS than 18%. Additionally we don't know what accounting tricks went into getting to that number. Considering PC sales went in the tank, this number would be far lower if MS was able to announce revenue only from end user sales.
Regardless, with Windows 8 MS has their foot in the door. The key is what they do now. If they are flexible and light on their feet, listening closely to the consumer and willing to walk away from their "vision" where it isn't working, MS and Windows 8 has a chance. However, that entire list is antithetical to everything MS stands for so I would be surprised.
The fact that developers are pretty much running from Windows 8 like a burning building, it seems a lot of people that matter don't have any more faith than I do. If developers don't get on board with Windows 8 it is already DOA as a mobile platform. Against Apple and Android if your App Store sucks you have no chance. The lack of Surface peripherals in the marketplace tells us that third party manufacturers want to see where things go before committing resources to large scale production.
The scariest part for Windows 8 and Surface is that they have no momentum. Without momentum third parties don't jump on board. Without third parties on board you don't have a compelling product to build momentum and that dog starts chasing his own tail.
Windows 8 and Surface Pro could be great in the same way I could have an amazing body if I lost 40 pounds. Question is, will I pay the price? Will Microsoft?