If the trend holds, we will increasingly see extremely specific application modules being developed instead of one-size-fits-all software. That, in turn, might erode the profit margins of software development companies as they will be unable to sell features that the customer does not want.
As this more distributed model evolves and services become less and less dependent on the underlying operating system, what will happen to companies like Microsoft, who tie things very closely with their operating system?
It seems to me that the software world is about the experience the kind of breaking point the music industry has experienced with the rise of Napster. Napster was significant not only because it allowed to share music but because it unbundled songs, making it difficult to sell a whole album solely because there was one of two good songs on it. If software features become decoupled due to web services, we could see software companies being forced to lower the price of their software packages and sell features on a new pricing model. Large companies like Microsoft will not be killed by large competitors but by the emergence of thousands of small competitors who will build better features.
An interesting trend that should be followed.