Very cool! Have a page or repo up to follow your work?
Current release plan is to get some builds out late August/early September, both free and paid(paid simply gets the updates faster). Then later on, I can think about plans to open up development. PICO-8 took about two years from conception to release and I'm getting to around the end of year one of mine, and just about everything has had multiple iterations, but the first release will be a basic "run at the command line, code in your text editor, store assets in the file system" kind of environment. Releasing means I think the basic design is mostly settled, so after that all the UI and IDE functions will become possible.