I think this will be a good way to create new jobs, and I am not sure if Obama really means it to be included in his 3.5 Millions jobs plan or not.
For example, even if Data.gov won't create API - which is less likely to happen -, I will create an API for Data.gov, and I will make a business model around it, and hire some programmers with me.
I have created API for Yahoo! Music videos long time ago before Yahoo! thinks of creating it's current music API. :)
APIs and making data accessable to others, and organizing the data and even mixing it like a mashup, is something that will help people for sure.