I’ve noticed lately that data warehouse vendors are dusting off the arguments and pitches of days gone by. Don’t buy specialized hardware for your database needs! You’ll never be able to re-use the gear! One rep recently told a client, “With your data warehouse on our hardware, you can re-purpose the hardware at any time!”
The truth is, while data warehouse failures were rampant a few years ago, those failures are now the exception and not the rule. Data warehouses, once installed, tend to last a while. The good ones actually add more data over time and become more entrenched among user organizations. The great ones become strategic, and business people claim not to be able to do their jobs without them. A data warehouse platform is rarely for a single use, but for a multitude of needs. Data warehouses rarely just go away.
However don’t confuse an entrenched data warehouse with an entrenched data integration solution. I’ll teach a class at The Data Warehousing Institute conferences called “Architectural Options for Data Integration.” The class covers technologies like Enterprise Application Integration (EAI); Enterprise Information Integration (EII); Extract Transformation and Loading (ETL, and its sister, ELT); and Master Data Management (MDM). I present use cases for these different solutions as well as lists of the key vendors that offer them.  Attendees I talk to admit coming to the class with the intent of justifying the data warehouse as a multi-purpose integration system. They leave the class understanding the often-stark differences of these various solutions. And I hope they return to work with a different view of their future-state integration architectures, whether they repurpose their hardware or not.

Evan Levy's blog can also be found at http://baseline-consulting.typepad.com/evanlevy/.