Interesting things from the FAQ:

From what enterprise data sources can Mashup Hub create feeds?

IBM Mashup Hub can generate Atom feeds from Microsoft® Access exported queries, CSV files (Excel worksheets are forthcoming), relational databases, XML documents, IBM Information Server, IBM DB2® pureXML™, Web services, and IMS (Information Management System) databases and transactions.

How is Mashup Hub's feed mashup capability different than Yahoo Pipes?

Mashup Hub feed mashup can be based on joins between feeds, and it has a special ability to process XML content in feeds, which is what you typically have when the feed is from an enterprise data source.

IBM Mashup Starter Kit