I think there should be sub forums instead of stickies like 'everything this' because you can be trying to discuss a certain thing about something and then 10 more posts come in about something else to do with this and its hard to see if anyone has replied to you so I suggest you make it so when you go in a forum section eg. Video Games their will be sub forums at the top in place of the stickies eg. Halo where you can go and post as many different topics about the Halo as you want eg. Favourite: Race, Weapon, Map, Halo Game etc. and not clustering it all into one big mess.
Also I they could add a 'reply to' part so if someone is replying to someone it could somehow tell the person they are replying to that someone has replied so it is easier to find when someone has replied to a post because alot of times I don't realise people have replied to me.
Feel to leave criticism but I think this will be a great idea and most people will agree.
There is a discussion thread for forums in AG3 here. I believe people have already mentioned subforums. But as far as anyone knows, they haven't decided on the forum software yet.