In the world of Hai:
You can now start text with an @ and a " to mention a user, who will be pinged about the post and any future comments. Typing an @ followed by a " followed by a user's name will pop up a list of everyone matching in your teams; click on a suggestion to auto-fill it.

You can now broadcast someone else's post by clicking Broadcast in the gray toolbar beneath anyone else's post. This will broadcast it to anyone who's added you to a team, kinda like re-tumbling.

  • You can have
    • multi-level
      • lists
      • using multiple *'s or #'s
      • at the beginning of the line

You can drag-and-drop images onto the comments text box to upload and embed them in your comment.

Lists of all Worlds and Rooms now appear on the main page when you're not logged in. That should get people curious. Anyone can click those to view the Worlds and/or Rooms.

I also fixed the compose text box so it will only show up if you're logged in. Oops!

Next on the list: You'll be able to cross-post to Facebook or Twitter, rooms will automatically update as new posts come in, and you'll be able to block users and export all your data.
Screenshot of Weirdness:

The background on "Mentions" in reply comments isn't filled.
@"SinbadEV" Thanks for the bug report!

Hmmm. What browser/OS are you using? (It's weird; that box very much has a background in the CSS, and I can't replicate that in any of my test environments so far.)
Oh wait, yeah, I'm seeing it in comments but not in posts. Weird. Digging into it now.
OK, found the issue (the comment box was restricted to a certain height). Fixed!
Chrome 38 on Windows 7

After some digging and manual CSS mucking I think it's a sorting issue. The background is there but it is behind the next post (while the text is somehow on top of the next post) so did some digging and found that in order for z-index to work in Chrome you also need to set "position: relative" (Chrome let's you alter CSS and I got the expected result when I added position: relative; to .reply-suggestions)
Your altering of the comment box height also fixed it (the comment box used to overlap the next post so now, since it doesn't overlap to begin with, the sorting issue is also a non-issue)