Andy_Langton - 11:54 am on May 4, 2012 (gmt 0)
To my mind, the "default" should be responsive design, so that everything works reasonably well across a broad range of devices. And then if you have the time, investment and business case to customise for particular devices or device categories, then that will obviously create a better user experience.
One factor is that the rise of "smartphones" has been pretty swift, and smartphones cope well with the same technologies used on many desktop sites. So everybody is playing catch-up with the technology to some extent.