At 1PM PST today, I'll be doing an MSDN Webcast on how to extend Integration Services including how to write new tasks and create new components. Why would you want to do that? Well, the simplest example would be if you have binary files that only you know how to read or have other existing business logic, you can integrate that with the product fairly easily.
In our presentations, we've been talking about the fact that Integration Services is a change in mindset from DTS in that while DTS was a useful tool, SSIS is really a platform for enterprise level data integration. This presentation is where the rubber hits the road and we talk about how do you plug into the platform yourself.
The webcast will be recorded for posterity.