ZA and ZG will have similar maps to the old instances
Deadmines and Shadowfang Keep were brought to 85 and were completely different. Completely. Different. Completely. Different.
It is new content in the end. Also, we're getting another water themed instance, so 4.1 is bringing 3 new instances. If you try to "run it" like the "thousands of times" you've run it before, you'll get rolled. Why? Because it is completely different.
The only thing being recycled is the theme of trolls and I'm honestly happy to get something out of place. The whole surreal and relatively elemental instances were getting boring. Even if it's been run before.