Based on your listed criteria (poster-sized enlargements and doing weddings), the choice is clearly D7000 as the price differential is not that great. Finally, the increased durability of the D7000 nails the choice.
I read earlier that you already own Nikon equipment so it would make no sense to change to any other brand as it would not be financially worthwhile. Plus you're already familiar with Nikon menus, physical layouts, flash systems and lenses.
In my past life, I've sold camera/camera systems retail as well as shot professionally. When upgrading from an earlier Nikon to the newer technology I grew into it quickly enough to not be intimidated or hamstrung by the sophisitcation. After all, you don't have to use every bell and whistle. You do, however, need to be able to find and access what functions you generally use for your 'money' shots.
This sort of familiarity only can come from putting your hands on the 2 camera models and using them either in the shop or on loan. Many retail camera retailers will allow you to borrow, a shop display model for a short period of time. All you have to do is ask (refundable deposit).