These articles look at the pros and cons of being so connected with your teen when they go away to college:
http://www.chicagotribune.com/news/ct-met-teen-connected-parents-20100805,0,7352817.story
http://www.courant.com/features/books/hc-iconnected-parents-college-kids-20100813,0,2262726.story
And this article offers advice from a student affairs officer at a college:
http://voices.washingtonpost.com/campus-overload/2010/08/letting_go_10_tips_for_parents.html