This is good advice from Peter Krantz:
TL;DR See if it is possible to publish your open data as file dumps instead of building advanced API's that force entrepreneurs to integrate their apps with your infrastructure.
Agreed. I'm still convinced that data is usually better than an API.
Via http://sunlightlabs.com/blog/2012/government-do-you-really-need-an-api/. Sunlight Labs director Tom Lee makes a great point in there about web APIs for GIS.