If I had a wish on this my list would be something like this. Others will have other wishes, but for now, I'm the first one to ask ;-)
add sdcard support. I'm working on a datalogger which collects data from sensors, stores on SD and prepares this data for JSON-calls from web client.
using flash for files, @tve talked about using flash for files, similiar to what nodemcu is doing.
have a plugin-interface in Espruino to add modules/functions. @Gordon already startet something like this with assembler and compile in original Espruino.
add flash-information to process.memory(), as original Espruino does.
for nodemcu there is a webpage to create "your own binary". Functions can be added or removed there. For example, if you don't need SPI or IC2, remove it and add, may be SHA1 support or other special things. This is a big big wish, I know.
Espruino is a JavaScript interpreter for low-power Microcontrollers. This site is both a support community for Espruino and a place to share what you are working on.
If I had a wish on this my list would be something like this. Others will have other wishes, but for now, I'm the first one to ask ;-)