Yes the rumors are true, Advent of the Mists MUD is closing at the end of July. Cedric and Crystal no longer place the MUD on the top of their priority lists, therefor it has just fallen to the way-side.
However the website and forums will remain up, for at least the next 2 years since it’s paid for. Crystal still intends to flesh out world theme stuff on the website as a hobby. We are leaving the option open to maybe reopen the MUD if we decide we have time/desire to do so. And because of that we are not releasing the code-base, despite several inquiries.
As a parting gift, here’s a youtube video I started at the end of 2008 but never finished editing. I was saving it to help launch us into beta when the time came