Yes and no. The library I use is for single wire. A new lib (or better, an extension to the existing) is required for I2C. But the logic layer can be reused assuming the api is kept intact (which it should, as there are no hardware specifics in the api). I considered using I2C, but rejected it in order to be able to be more versatile and less dependent on pins and components. But the device register map is identical between the devices so it is enough to switch the data marshaling parts.
The library is based on this:https://github.com/jimblom/sha204-Breakout
But I have made a few changes to it to make it more suited for device use. You can find my lib in the development branch of the MySensors git by now. It also carries a sketch to personalize the device.