There is a very interesting presentation at http://www.slideshare.net/yiibu/adaptation-why-responsive-design-actually-begins-on-the-server . It covers the challenges in responsive mobile site creation, and proposes a hybrid solution of device profiles to solve it.
The first half of the presentation is worth showing anyone who does not understand the challenge of developing a mobile website that works well on multiple mobile devices, not just on the latest and greatest iPhone / Samsung / HTC.
It’s strongest point is that many people (especially in this current financial climate) will not have the latest leading edge device. In fact, your cutting edge, state of the art device from 2 years ago (read iPhone 3/3G) is now old and destined for the mobile device rubbish heap. However many people will not automatically upgrade, but will keep them, and thus there is a great proliferation of devices which don’t support the latest HTML5, slower Javascript, etc.
Added to this is that the word ‘smartphone’ retains a nebulous definition, and in fact today’s ‘cheap’ devices contain most of the features that a smartphone has (e.g. touch screen, browser), however their ability to serve the web may not be as perfect as Apple’s Mobile Safari.
This is the reason that content adaptation has had a number of solutions, via examples such responsive design, server-side detection and adaption, etc.
The solution proposed in this system is not a simple solution. It proposes an aggregation of device information (e.g. from DeviceAtlas) on top of a default device profile, stored in cookies, sent via Javascript to the server to analyse. To implement it for a client, I for one would hope to see a library to help achieve this without the larger development cost, so I will be watching closely.
There are also some interesting suggestions at the end of the presentation about some potential options for the future, e.g. changing the <img> from having one source file to having multiple source files (similar to the way the <video> tag is currently done). I would be interested in this option, however the reality is that the HTML change process is long and tortuous and thus I won’t be holding my breath.