The tactical data-oriented integration products such as the ones you name will always have a market. These tools provide limited features but a compelling price point. They cost a fraction of what you would pay for a true integration broker or application server, but they provide a fraction of the capabilities as well. You have to analyze your needs.
ETL tools, generally speaking, are far ahead of what the database vendors offer, so I would say their future is safe as well, at least in the short term.
However, I would not say that the market for the above products are expanding rapidly.
This was first published in February 2002