yes, certainly… depending on your threshold for “hassle.” 
i’d think it would be sufficient to implement the monome serial protocol and apply it to the stream from an arduino Serial object or whatever. on the host side, i think serialosc should work fine with any TTY device that obeys the protocol.
the “canonical” implementation would be of course in the grid firmware. it’s not exactly easy to read / port, but it is straightforward.
a nice clean c++ implementation would be great to have, and several times i’ve found myself just not quite motivated or available enough to make one…
if you just want to use OSC messaging format on some arbitrary transport layer, i would use the oscpack library which has minimal dependencies and can be easily added to an arduino project.
maybe the main point to make here is that monome devices are just TTY serial devices, just like the serial port on an arduino. data is pushed and pulled in the normal way - on *nix’s, by polling and writing to a regular ol’ file descriptor.