To me its just a fun little thing I'll try to do over the weekend and hopefully it'll offer a bit of refreshing perspective into web-based app development again since I've been stuck in the flex world (what pays the bills for now) for so long.
But actually his post offers a pretty good to-do list for the list of things I need to do to get it working, so basically, there is:
1, Asking and Responding to question 2, can't downvote person too many times in certain amount of time 3, spam bot detection/prevention 4, user icons 5, sanitizing html lbrary 6, karma 7, full-text search with search-as-you-ask 8, user bios 9, important questions that bubbles down slowly 10, bounties 11, email notifications 12, javascript smart tags 13, user configurable badges 14, history of karma, upvotes and downvotes
and oh yes, I'm not going to attempt to implement the design, i'll prolly start off by using the stackoverflow css and html as a template like what cnprog did when they started off and perhaps let someone else ( or do it myself ) replace it later.