I doubt the feature phone market will last much longer in developed markets.
Nielsen: Two Thirds of US Mobile Buyers Choosing Smartphones [blog.nielsen.com]

During Q2 2012 smartphone penetration continued to grow, with 54.9 percent of U.S. mobile subscribers owning smartphones as of June 2012. This growth is driven by increasing smartphone purchases: 2 out of 3 Americans who acquired a new mobile phone in the last three months chose a smartphone instead of a feature phone.