I'm interested in what sort of mods and custom content people would like to see, or make themselves, when CE3 Sandbox 3 and a modding tool is released to the public.

I've constructed just a quick list of custom content (mod) categories:
? Graphic configs
? Models/assets: palm trees
? Singpleplayer: a whole new sp in the jungle!
? Multiplayer: vehicles, larger player counts and power struggle etc
? And whatever else I forgot...

I myself want see the exact same Crysis 2 campaign but with Koreans replacing the cell guys and aliens, but keeping the same AI in C2. I think that'd be funny. I also would like to see the complete Crysis 1 campaign but in the new engine and the new suit.

Mods anyone?

Crysis redone on CE3 is a given for many I'd imagine. That mech warrior mod they had going for the original cryengine looks promising as well.

If I had the time I'd contemplate contributing to mods but hah, like that'll happen. Best wait for the sandbox to come out before we think about too many things...

i want to see an "Hunted" Mode
one player plays alcatraz and all others are Cell soliders Hunting Him
Who kills Alcatraz Most the times in 5 minutes plays alctraz next round

Nothing.

I would gladly make some maps in it like I did in sandbox 2, but I don't really think there's going to be an editor released.

If I can get the editor I will boot up my computer and go mapping crazy!! I only made 3 levels for Crysis 1 / Wars MP... 2 of which are on the internet. I plan on making plenty of maps for Crysis 2!!

If the DX11 patch doesn't fix all of the texture problems, I would like to see a texture mod.

http://www.videogamer.com/news/crysis_2_dx11_patch_confirmed.html

If you doubt the DX11 patch, read this^

I hope the standalone editor will be compatible with Crysis 2 this Summer or I will be quite annoyed with Crytek.

There's a difference between a CE3 modding kit and a Crysis 2 modding kit. While we're definitely going to see the first, I doubt we'll see the second.