Hi Ben,
I've been slowly chipping away at a project for some time but my skills with the pi are just not to the task and I think the micro is well suited for the task. The project is a "Wind talker". Such devices already exist, but they are usually propriety units and expensive and not very hackable. I had planned to build a wind talker using a PIC chip and a TTS (Text To Speech) chip. But TTS chips are a child of the 1980's, their voices are rough, robotic and hard to understand.
Modern TTS chips with a soft human female voice just don't exist.
Instead TTS engines are imported into operating systems like linux. So a stand alone serial TTS chip or board would be a great tool for embedding voice abilities into very small projects. The raspberry pi and now the pi zero are well suiting to running TTS engines. But I'm a PIC programmer, i program in assembler and construct projects on the SMD scale.I The OS and I often get into a fight over who owns hardware. 
The windtalker project I'd like to see would use generic anemometer and wind direction vane which has a standard interface like I2C/SPI/RS232 which can be interfaced to the micro controller connected to the audio of a radio like a UHF CB. When the unit is activated by DTMF tones etc the wind talker then broadcasts in a nice clear voice the windspeed, direction, temperature etc as well as battery voltage and any other alarm conditions.
You want a unit to be bale to tell you it needs help if something is wrong.
So while building an open source wind talker is the goal, it would make a like more small and embedded projects better if there was a modern TTS chip or small module without a robotic voice.
Thanks - Ash