OK, the IM system has been implemented. (Controlled by the chat bar at the bottom of your screen.) It still needs a lot of tweaking and I can certainly entertain feedback on it via PM. Some things to know about it:
1. Multiple chat windows currently appear on top of each other. Not much I can do about this, although you can drag the chat boxes around.
2. If you have multiple tabs of SMNet open in your browser, the newest messages may wind up only showing up in one tab of chat.
3. Chats are updated every 10 seconds in order to keep server load at a reasonable level. The "Who's Online" window only updates when you move from page to page or refresh the page.
4. It came with some widgets that let you share pages on Facebook & Twitter, along with quick bookmarks to the homepage and your message inbox.
5. It's only implemented in the default theme. Fans of Overview and Mystic Jade, I know the themes are kind of broken right now, I'll get to that as I can.
6. Old messages are saved for 24 hrs.
7. Works in IE8, Firefox, Chrome, Opera, Safari (for PC). Haven't rebooted into OSX or Linux yet to test, will do shortly.
8. Mute chat sounds using the little speaker button in the bottom right corner.
9. Invisible peeps show up in the list of Who's Online. Working on this. Right now. Fixed.
10. Most recent chats appear at the top of the window. This is backwards from what I'm used to and needs a little adjusting.
More as I learn it...