A suggestion. Not sure if it's be suggested. Sure it has. But let's get people to sign on!
Lets get fan made packs. Like...take the top 25 most practical fan mods. Like better physics, map etc.
And release it for the console people.

http://images.uesp.net/c/c4/Fishystick.jpg
Have a fishystick. (business first, I'm sure you understand)
That could garner a lot of red tape, I'm afraid.

Explain .

Far Cry 2 ...has a multiplayer map maker. Very simple. It's shared online.

I'm not saying it's a bad idea. I'm just saying it would open up a can of worms. Rights issues, coding, cost, time, and all that, I won't go into details. Multiplayer has never agreed with Bethesda really. The only game of theirs to have multiplayer is Battlespire, but since then they haven't really liked the idea much, I suppose.

You're posting this in the wrong forum.

You need to take your ideas to the manufacturer of your console... because they are the ones who blocked access to user-created content (ie: mods), not Bethesda.