Here are links to some useful advice about deferral:
https://alumni.brown.edu/services/advise/app-outcomes.html
http://thechoice.blogs.nytimes.com/2010/02/09/defer/?_r=1
http://inlikeme.com/how-to-handle-a-college-admissions-deferral/
http://www.collegeconfidential.com/deferral/
http://collegeapps.about.com/od/theartofgettingaccepted/tp/deferred.htm