The rumors I've heard have said the existing UoE building will be used for queue (something UoE has never really had) and preshows/exit shows/gift shop. An entirely new ride building will be constructed behind the existing structure, where the permits have re-routed the drainage canal from. The new ride may slink out behind the old WoL pavilion a little as well.
I guess we need to keep in mind that the existing show building for UoE is not that big. There's no queue in it for one. And the ride makes it feel bigger, but the first room and final room are actually the same room, just with different screens being utilized. There's the first/last room, dino scene, and middle theater. Add that to the skinny preshow holding room and it's actually not that much space.
And I highly doubt all we'll be getting is a retheme of the existing Energy ride (hopefully.) I bet they gut that building completely and use it just for queue, preshow, gift shop, and maybe load/unload for a new attraction.
But that's just what I think and the rumors I've heard. Clearly Disney isn't ready to release any real info on the ride type just yet. Could be interesting.