I worked through Win 3.1, ME, and Vista. I had a lot of clients to support through those. Those versions had a very small test base, and they did not have frequent updates. It was a problem.
Windows 8 has had the largest pre-release distribution of any software product, ever. Built right into it is an ability to instantly send your feedback to Microsoft for the OS, and the developers for any applications ! Its right there in the the Charms !
I see updates coming out at least once a week, and more often on many products. The Store updates apps all of the time. I often see 12 available in a morning, and I don't have many more than that installed. I also see major and minor updates are auto installing in the OS. Even the development tools have an accelerated update schedule.
This is the most widely tested release ever of Windows. I read a lot of reviews. The negative ones are usually by Apple gurus who "looked at" WIn 8, and then try to compare it to iOS. That's all wrong.
Time will tell, but right now developers are on the leading edge of creating apps. In the RT environment there are lots of games, news readers, social software, and of course the full Office Suite. So far there is a big need for Line of Business apps, and those who can develop them will find an opportunity for a very good income. The demand will be large, and the competition small. Of course that picture changes for those who wait.