There's a very nice article by Marc Drummond on responsive design, To hell with bad devices: Responsive web design and web standards, which covers lots of the points I've been thinking about recently. The one that really struck a cord is in the Responsive vs device-specific design: Workforce considerations section: there has to be a balance between having just a small screen and large screen version and having a whole basket of breakpoints. It has to stay practical.
Responsive design is exciting, but it's also very new and the web design community is still figuring out how it works and what to do with it. Luke W's famous Mobile First approach combined with responsive design is a very pleasing way of approaching a new project. I think that the wide side is the most challenging to deal with: what do you do when you've got over 2,500 pixels of width to play with?
Marc's article also contrasts nicely with the vaguely trolly article by Luke Jones that's been doing the rounds the past few days.