Chogon has posted a small update on the MOUL forums
Hi all,
This is all pretty exciting! So many old faces. Just a quick note:
There is still work to be done to ready the sources for open source and many small details to be worked out. Things will be released in stages and I am positive that the first to be released will not happen until after the first of the year.
(BTW, it is very tempting to call it Open Source Myst Online, i.e. OSMO. But that might be confused with Cosmic.)