Here is "60mins" interviewing Joel Osteen. Dr.Michael Horton is also interviewed, but not for long.
http://www.cbsnews.com/stories/2007/10/11/60minutes/main3358652.shtml
And here is a link to an article Horton wrote about Joel Osteen and the problem with his message: http://www.wscal.edu/faculty/wscwritings/horton.osteen/glorystory.php