I honestly don't remember him going after Islam. So I really don't see where he did a "180"? I just don't remember him doing it.
2006 WASHINGTON — CNN TV host Glenn Beck tells NewsMax that he believes “Islamic extremism is the biggest threat to our way of life since World War Two and we’ll never be able to fight it if we can’t see it.”
http://archive.newsmax.com/archives/articles/2006/11/14/170416.shtml
2007 Glenn Beck : Radical Islam Exposed - http://www.youtube.com/watch?v=bYXAWgY__1w
2008 Glenn Beck on Islam
http://www.youtube.com/watch?v=VjS_0mbKH7I
Feb, 2009 Glenn Beck interviews Geert Wilders on Islam and the Koran -
http://www.youtube.com/watch?v=FhwU4rvbxKY
I don’t know if he has done anything since then.