There is a book about the "bubble" of string theory research written by a physicist, but the title and author slip my mind right now.

It discusses the very phenomenon that research grants go to increasingly bigger groups that can be trusted to deliver. And also string theory research itself which did get a ton of grant money during the 1990's even though the results never had impact outside the bubble itself.

Edit, some searching helped me find it: Lee Smolin, The Trouble with Physics http://en.wikipedia.org/wiki/The_Trouble_with_Physics