Don't think anything is being removed- only blue response on the topic I found is here:

http://forums.worldofwarcraft.com/th...79539&sid=1#15

Q u o t e:
Not sure if this has been addressed yet but what (if anything) is happening to the dungeons in the zones that are changing? For instance, Scholomance and Stratholme will be over the level of the zone that they will be in. I suppose blizzard could just change the levels of the mobs inside the instance, but that could also be confusing and might be a piece of vanilla wow worth hanging onto.

Those dungeons (and more) will get some love.
Lead World Designer