I have some ideas firstly I think it might be cool if it was possible if you can set as topic starter your topic as solved or unsolved. Then other users can choose in there settings or the administrator can force it that in the forum solved topics are shown or hidden. It would also beeing nice if the topic starter can mark some of the messages as the solution of his topic and the administrator can set for each forum how many posts can be the solution etc.
Another nice thing would be the topic tags this is also nice I think i don't have to give some explanation about this
On a popular dutch site I saw this tool users can rate messages in topics as "verry informative", "normal reaction", "bad reaction". Then users can choose which level of reactions they will see so they can choose to only see verry infomative reactions. The votes of members are controlled so members who always vote bad reaction can't vote anny more. I don't know how this can be done in real but is saw it on Tweakers.net. Maybe it can just be done with giving topics ratings but than not with user moderation like i said.
And something a normal forum just has to have these days RSS syndication, this is not so much work maybe one week developing on a low level and then you have a verry good RSS system with extended functions.
It would also be nice if there was a kind of code tag were you can add code templates for which can be easily installed.
And a reputation system would also be nice
What do you guys think?