What is enterprise mash-up?

If the mashup is an enterprise mashup, it means that its creator intends it to solve a particular business problem. Then, tight coupling between provider and consumer software would be a serious concern.

Enterprise mashups strives to meet business needs, therefore, will require SOA, and the SOA infrastructure necessary to guarantee loose coupling. Without that loose coupling, mashups are little more than toys from the enterprise perspective.

In mashups, applications are unleashed and integrated in new and interesting ways with other types of applications. That's also the guiding philosophy in SOA, in which applications are broken down into granularized service components that can be mixed and matched with other services as business needs demand. And, theoretically, could be assembled on the fly by the business folks, versus sending work orders to the IT department. And, theoretically, such services can come from outside the walls of the enterprise.