A very nice development. I like the AT90USB162 for its native USB interface (no serial unless you build it). I find this makes the code for host communication cleaner as it dispenses with serial parsing and all the error handling that comes with it. The lack of analog inputs hurts on the '162. Even for nominally digital applications, I find it handy to use the analog inputs for things like instrumenting currents and secondary voltages.
For the folks mystified by Arduino popularity this may be your preferred solution (lower cost, more capability). My personal opinion is that Arduino is not popular because of the hardware or software, but because of the culture. It is deliberately kept accessible to people that don't know fancy words like "data direction register". You can look at the examples, do a little copy and paste, make some breadboard connections and build that special little object that you thought should exist.
For the folks mystified by Arduino popularity this may be your preferred solution (lower cost, more capability). My personal opinion is that Arduino is not popular because of the hardware or software, but because of the culture. It is deliberately kept accessible to people that don't know fancy words like "data direction register". You can look at the examples, do a little copy and paste, make some breadboard connections and build that special little object that you thought should exist.