Ethan Marcotte's responsive approach to designing for multiple devices has certainly been a game changer in the 12 months since its inception. However with the myriad of device widths available today, media queries set to specific pixel based dimensions for specific devices is not scalable.
Our neighbours Front may have found a solution in 'The Goldilocks Approach'. Instead of targeting popular device widths, they take a ems based 'content-out' approach.
Front's approach starts with the chief building block of any page, the paragraph. By leaving the text-size as the default value set by the manufacturer and setting the max-width in ems to the values that affords a 'just-right' reading experience, we have a true device independent responsive approach. Devices will fall into one of three categories, 'too small', 'too big' or 'just right'.
We've implemented aspects of 'The Goldilocks Approach' in the new Rumble Labs website where we could. We recommend you consider doing the same!