Here I will list some new features being added to the forums:
avatars are now up to 200x200 pixels @ 100KB max
upvoting is available (downvoting is not, but moderators can clear the upvotes for wrong grammar posts if necessary)
more language packs (if yours is still missing - please, tell me)
I keep adding more duolingo graphics to make this place more familiar
stickies (you need to edit the first post in a topic to make it a sticky)
a custom RTL BBCode while editing - for posts in Arabic
custom BR/LB BBCodes for line breaks
a BBCode for FontAwesome icons
[fa]arrow-left[/fa]
(cheatsheet: https://fontawesome.com/v4/cheatsheet/)
YouTube is also working now, as well as many other "media" links
Duolingo Username field and country flags in your profiles - these flags are being quoted on the front page next to your usernames, adding a little more flavour to the forums )
And here's something new for duome.eu profile/progress pages:
Daily progress chart is now 30 days wide
Daily progress chart is now full-size and scrollable on mobile devices (auto-scrolls to the last date on the chart)