I would come down even stronger on this and say your next website MUST be responsive since to do anything other than that is goofystupid. Mobile is only a tiny bit about your phone. It is mostly about data structure. If you work backwards from how to make data look great no matter what kind of device is receiving and consuming it you end up changing some recently cherished ideas such as:
* The graphical role (all but dead in a mobile first world).
* Heavy graphics or heavily layered CSS (mobile can't take the weight).
* Lots of server side calls (got to be crazy to call out for anything, cache it and forget it).
* Too clever anything.
Read Krug - Don't Make Me Think and then double that and start your design with your mobile site and at the data level and you are create responsive design.