...as a side note, Duke's Dean of Admissions, Christoph Guttentag, holds Eagle Scouts in particularly high esteem, as he mentions specifically in this video from a couple of years ago.:
Ask Admissions with Christoph Guttentag, a discussion of Duke University admissions policies dukeuniversity on USTREAM. Educational
As far as how EC's are evaluated, the important part of this interview comes just after the 13 min mark when Guttentag outlines that Duke is looking for IMPACT in activities, not necessarily just participating, or even having a leadership position, but "what impact did you make?". So, if you are outlining what you did as an Eagle Scout, make sure to highlight the impact you made, not just that you were an Eagle Scout.