Two additions would be really cool (I'm thinking about adding them myself):

1) Expose the environment as virtual folders (like /proc in linux). So that an object in memory coincides with a file in a directory, that in turn would work like a package. For example "ls" would live under /env/fs/ls (and /env/ls would be in "path" for symbol evaluation).

2) Expose the dom, always as files (/env/dom). Make it a plugin. Add a lisp repl to every webpage.