xcoder - 12:31 am on Sep 21, 2012 (gmt 0)
It might help to note, without getting too specific, what niches are being affected by a shift to mobile.
Trade and health services, institution and BM shops (opening times and addresses pages in particular), TV/Cinema/Events guides... etc. etc.
I think it would be safe to assume that most if not all websites must be mobile friendly nowadays.