I have a feeling Stack Exchange sites are appealing to the role-playing gamer sides of its users. If you look at reputation, it's similar to XP earned in RPG games like World of Warcraft, Garena, Diablo, etc. Answering a question and getting it accepted is akin to succeeding a quest, and so on so forth. Things like voting, bounties and badges especially look like MMORPG elements to me.
So this kind of software which actively rewards folks for feats while providing a profile which they can potentially show off on other sites/personal blogs etc — into which genre can we put it? Here it also shows top-rep people — sort of a ladder which you can climb up, and gives you occasional acheivements like "Scholar", "Autobiographer", etc — very similar to trophy collection in PS3. By the way, PS3 profiles also have badges, which you can put on other sites.
Going further along this line of thought, what other elements can we bring in? Can we bring in items that are purchased by reputation (e.g., software items like a larger profile picture or a real-life SE C# certificate), or something similar to spells (e.g., necro-question-mancy — reopens a closed question once), and even set up P2P combat (e.g., 2 people with high rep can challenge each other to answer a question and a reputation transfer happens when one of them is accepted).
Let me know what you guys think on this subject, and also if you have a name for this genre of software.