It would be nice to merge similar topics or have more specialized categories. for example I started a keypad discussion While there already was one going, if there were a place for inputs and subtopics such as keypad, wii nunchuck, analog,
a subtopic for LED projects
subtopics for widely used peripherals.
Choices of key words would be nice as well.
people having choices of keywords that would allow people to either use the forum as is, but also have the choice of browsing the different keywords
when there is sufficient interest in a certain topic, a playground wiki page would be a nice addition where people involved in the discussions are encouraged to condense the conversation into a single wiki article. that way when a topic in a discussion gets to be repetitive, people refer others to the proper wiki page so people can get up to speed without someone having to explain things over and over. in the forum searches it would be useful to include results from the wiki, so people can see the condensed version and simple questions could be avoided.
another aspect to this is code. having speciallized projects that people can start with and from there engineer it to their needs, and post updates they made and allow people who use the different examples to rate how useful they found it.
just some ideas that could help people get the most from and the wiki and streamline the discussions.