The answer to this question depends on the context, i.e. the market with respect to which we are asking it.
According to Christensen, most new technologies improve product performance. He calls such technologies sustaining technologies. In contrast, he identifies disruptive technologies to be those innovations that lead to worse product performance, at least in the near-term. He goes on to say that such initially less-performant technologies end up precipitating the leading firms' failure.
Christensen also notes that there are three reasons established companies do not invest in disruptive technologies. First, because disruptive technologies are simpler and cheaper, their use only provides low margins to begin with. Second, disruptive technologies are usually first commercialized in markets which the established firms consider to be insignificant. Third, established firms' most profitable customers cannot initially use such technologies. According to Christensen, a practiced discipline of "listening to customers and identifying new products that promise greater profitability and growth are rarely able to build a case for investing in disruptive technologies until it is too late."
Frankly, I am not sure I agree with this last point Christensen is making. I think listening to customers does not just mean listening to what it is they want. Often customers don't really know or think they know but are not sure if what they want jives with what's "there." The most important thing companies should listen for are "requirements" in a deep sense of that word, i.e. not what a customer wants from us but what their goals are, how they go about achieving it now and how they can go about achieving it in the future. This approach is quite different from just seeing what they want.
So, is J2EE an example of a disruptive technology in the Christensen sense of the word?
Well, in the enterprise market, J2EE has been proven to be the de facto platform because one can easily develop, deploy and maintain scalable applications in production environments. So, one may argue that in the enterprise market, J2EE may not be as disruptive as it once was. This may not be completely true. While some real innovations (such as JAX-RPC and Connectors) have emerged that are not just about "performance" in speed, some may still argue that these new innovations are simply about "performance" in integration. They may have a point.
However, that is not what I wanted to talk about. What I want to say is that Christensen's notions of disruptive and sustaining technologies really need to be applied and scoped with respect to particular markets.
So, let's ask the question again and scope it to the telecommunications market.
Is J2EE a disruptive technology in the telecommunications market?
Applying the Christensen analysis, we have no choice but to say that it is.
There are three classes of telecommunications applications where J2EE has a good fit as the emerging and disruptive middleware platform: OSS/BSS applications, service applications, service control function applications.
Who will take advantage of this opportunity will be offering the next-generation platform for convergence applications.