Guns, grenades, spawn points, and maybe night vision! You could do this with the regular minecraft server software (1.3_01), yet bukkit allows so much more possibilities. EDIT by Moderator: merged posts, please use the edit button instead of double posting.
The plug-in War creates a warzone, which resets after a match and it also gives players teamcolors, and keeps track of the score.
The plugin im requesting will have guns and grenades, etc... yet bukkit doesnt support adding of new content :/
You'll need more than a server plugin for this. You'll also need a client mod. Server's cannot add CONTENT to clients. It's impossible with Minecraft as it is now. Server's can add functionality, yes, because the visuals and the means already exists. Hopefully one day there will be a way for servers to send content to clients, like in Source games.