They are counting on the huge rock formations and trees to serve as the transition, much like the castle walls at MK for the New Fantasyland.
I believe much of it will be hidden by that last shop on the left as you go up the street.
The picture attached is exactly what it will look like if you look at SW land from the hub. They may take off a portion of the Frozen building to set it back a bit more, but that's basically your view.
*I mistakenly marked the building on the right as Sounds Dangerous. I believe that's the Frozen Theater. As I said earlier, the rock formation on the left is actually in the foreground and the new attraction will be behind it (where Indy is now).
[EDIT: no, I was right in the first place. Sounds Dangerous is marked correctly and the Frozen theater is in front of it on the art.
From the DL map, it would seem Echo Lake would remain at DHS too since there's basically a body of water in the same place at both parks.
One thing I think people need to remember, DHS is not Disneyland. It is not some sacred park that is viewed as a church by many. I'm sure sightlines, etc. are considered, but they aren't going to spend an extra $100 million to make a better transition.