As I have said in various other posts elsewhere, it is my opinion that Windows 8's measure of success will be how well it will be adopted into the business world. Since most of the business world just completed upgrading to Windows 7 from Windows NT, I suspect that most of the business world will ignore 8 because the cost of moving to 8 is hard to justify after having just moved to 7.
Also, 8 brings little in the way of improvements and also brings with it (for the business world) the typical "wait and see if its stable" attitude of all new OS releases from Microsoft. Because of this, I see 8's acceptance in the world being more of a whimper than a bang or a storm.
As enthusiasts, many people on this site jump right in to the latest and greatest products without much regard to the consequences; however, I see the business world as much more conservative. Personally, I do not see 8's success without the business world buying in. I think there is little doubt that 7 owes a large portion of its success to the business world's buy in. I think Microsoft is gloating in 7's success, but may have an attitude adjustment on the horizon.