So you know how big servers have commands like /home, /spawn, /kit, ect.? All they really do is teleport you somewhere or give you something, both of which are existing commands. You could set custom commands to do commands that are already in the game, so for example, /home could be set to /tp 416 68 213, which would teleport you to those coordinates. You could also set who would be able to use them (ops, everyone, selected people, or those of a certain scoreboard rank.) this would help lots of servers not need unnecessary bukkit plugins.
I just think it would be easier to not have to make/download a pluggin when you can just make one in game. The key is to maxamize the potential for servers without downloading stuff.
http://goo.gl/65fcWQ and click continue.