hey folks, here some ideas I have recently, and I hope these ideas sounds to you so good like it sounded in my head ^^
1 - Better Trees (like Better Grass)
A simple modification, more a texture mod than a script mod.. it's just to change the texture of the top and bottom of some wood blocks, to the same texture it has in its sides. Just to make the branches of the biggest trees a lil' more realistic. I don't really know how to explain in which conditions the texture would change (scripting), but at this point you maybe had understand the idea.
Sorry if there is a mod for that already, though.
2 - Zombies' Night
This one would depend of a second mod, in which he moon would have its phases, changing between these in about 2 days, for example: 2 days of waning crescent moon, 2 days of new moon, 2 days of crescent moon, and finally 1 day of full moon,
totalizing 1 week in this infinite process.
The thing is, in that only night of full moon, zombies would spawn like never before (maybe in this day, other mobs don't spawn, it is up to you), doing more damage, and, if possible, this night would last more than normal.
just ideas, but I really expect download these some day ^^