This is the new area for submitting ideas, as it is more appropriate.
1. Use the me command, command blocks can dump custom map related flavour directly into the player's chat box. This can be combined with repeaters to give delays or make sure all the text arrives in order.
2. XP for Item Shops. Use give command in combination with a filter to exchange XP for Items. Inspired by MrABgaming and SethBling.
Two Command blocks stacked, with a repeater on a single block.
Top Block Command code: xp -1l @p[lm=5]
Bottom Block Command code give @p[lm=5] 256 1
This gives an Iron Shovel for 1 xp level, provided you have a minimum of 5 levels.
example video: http://www.youtube.com/watch?v=ZDlyLi6ztSg
- admins, please review, many thanks
3. A "dispense <direction>" command, to make command blocks drop or shot items like dispensers do, so you can obtain an infinite dispenser.
4. Some form of conditional statements. (EX: Command checks to see if player has a specific item (named using the anvil) and performs an action if the player has that item) or the block could maybe detect time of day as well.
5. Add colored text options without the need for mods or plugins.