It depends what you mean by “Web Services”. There are two core ideas, taken from the Web (hence the name). First, instead of trying to define APIs across networks, you specify the messages that are exchanged, and second, that XML is a decent data format for the messages. I personally believe both, and this is the only sane way to integrate applications in a heterogeneous environment. Unfortunately, the attempt to standardize this excellent idea, under the WS-* label, has gone off the rails. It is insanely complex, baroque and abstracted, and implementing it requires reading hundreds of pages of poorly written, unstable specs and dealing with ferocious inter-vendor politics. Fortunately for the future, there is a rock-solid base of proven, efficient, scalable, standardized technology: HTTP, XML and so on, and some very clear guidance on how to do things: REST. So, I expect WS-* to fall far short of expectations, but Web Services, done more simply, to be the default way of doing things in the future.