Earlier today Luke Wroblewski published an interesting article listing the number of new devices announced since the beginning of September. It brought back a thought I tweeted last week regarding device sizes and designing for the web.
It's not a new thought, lots of other far more intelligent people have been saying this for a while, but the post above really helps to illustrate the sheer number and speed devices are being released these days and that our initial thoughts on breakpoints might need a slight revision.
I'm not one to say designing with device-lead breakpoints is wrong, everyone as their preferred way of doing things, but designing this way does tie your hands somewhat and will likely cause problems down the line. I'm reminded of a quote by Andy Clarke* which, despite being a year or two old now, is still very relevant:
Writing CSS based on current stats is like building a single lane road because there are only a few cars. Plan for the future.
Setting up your media query breakpoints that are appropriate for the design will allow you to cover the most bases regardless of the device screen size.
Most definitely plan for the future, it arrives much sooner than you think.