I worked for a management consulting company and produced such a system based on aggregating data from across a global corporate network and producing dashboards in SharePoint.
Yahoo could have an enormous impact on KPIs, dashboards and metrics for consumers and business were they to want to. And with it, one hell of a revenue stream.
IFTTT could solve data/metric aggregation for consumers, marketeers and other less technical users.
And if an export from IFTTT could produce a Yahoo Pipe, then a developer (or slightly more skilled user - a good Excel user perhaps) could then make it do even more.
It could be used to read from Excel. From CSV. From SharePoint. From databases. From web pages on the internet and intranet. Everything.
Aggregate news headlines concerning your company. Create cohort charts with data from different and unconnected systems. Combine data from servers to mailing list campaigns to observe impact much quicker and to identify fully which campaigns work best. Or just grab the numbers from many systems to find out which system is showing the wrong value.
So much is possible that companies struggle with today because their data is siloed in disconnected systems... or some of it is external and they have no interface to it.
Glue between Twitter and App.net? That's just trivial. A real prize will be to aggregate anything and everything and allow it to be processed before reporting on it.
It's not glamorous... but I can say from experience that the company I worked for successfully sold the product I made for £50k licenses to large companies. The demand is there.