Does anyone know if there are any plans to release something like the GECK for the Xbox 360? Or maybe a way to download the mods onto the Xbox?

No, no.

The 360 couldn't run either the GECK or the vast majority of user made mods that aren't "here is a pistol it does 99999999 damage"

GECK requires windows files (dll's and stuff)... won't run on xbox. User-made mods aren't allowed on xbox... microsoft doesn't want free competition to their walled garden.

The G.E.C.K isn't available on the Xbox 360 or PS3, it's a PC-only software and it will remain that way.

By the way, we can't discuss console modifications here.

Nope, will never happen. It's PC only.