Technically, this isn't a feature so much as taking out a limitation. An unnecessary and occasionally annoying limitation, IMHO. :P
It's for in the cases of debates and such. We don't want people changing what they said after someone calls them on something, or something along those lines.
Also against this, for the same reason Killa posted.
I wonder if it could selectively be changed for the 'Forum Games' section? It wasn't bugging me until I started posting there, but sometimes you want to be able to edit your posts, if you're roleplaying.
Similar to what Killa said. Specifically toward those who troll or create fake accounts for trolling. Although it would be helpful with the 'Forum Games' section, it would take some time for alexp to do. The 'edit' feature wasn't even available until the creator updated the site.
I'm against this. The benefits would not outweigh the cost, especially in the forum games section since it's important to keep a record of everything that has happened in a game. People retroactively editing that is not good.