Seems like the executive mandate is an "80% now" solution instead of waiting for perfection. At least they're thinking about the dissemination of information.
If the President of the United States wants to be impressive -- and I don't know that APIs are where one would start -- he can do better than make announcements.
For example: http://ideascale.com/userimages/sub-1/736312/ConOpsFinal.pdf is a document (Dec 2009) documenting the vision for Data.gov, and http://www.whitehouse.gov/sites/default/files/omb/assets/mem... is a memoranda from 2009 that first started requiring the online sharing of major datasets.