I was mulling this over and this will be my next server. Currently I'm hosting 5 servers but this one will be the scariest server around. So heres the idea, if you've seen the movie pitch black you would know. I'm coding plugins as we speak to make this server insanely scary for Halloween. So....
For the 1.8 Update (Craftbukkit premitting)
Codename: Pitchdark
"Imagine a world cut off from civilization, totally dark from the ever shadowed sun, something hiding in the shadows."

Will Include:
Constant Dark
Endless Mobs
Iconomy
Mob Bounty
Bettershop
Ect.
Plus....
Burnt Out Torches ( indev )
- Torches will last a specific amount of time and then drop.
Mob Radar ( indev )
- Will scan a set radius for mobs and notify you of they're distance.
example: Enderman 4 Blocks Away

I believe this combined with some home brew Plugins plus the added Enderman will make for an insanely creepy and fun server.

ETA: Shortly after 1.8 update, Craftbukkit permitting, and alot of hope.
This Fall (at least)

Notes:
Looking for coders to help with mysql support and permissions coding.

Lastly my servers will remain stable.
Suggestions, Ideas, Criticism, or Help is appreciated.