While some construction remains closer to Cinderella Castle I saw most of the newly remodeled Hub unveiled in early March, 2015. I also watched Wishes and Celebrate the Magic from the new FastPass+ fireworks viewing area, near Casey's Corner, so I got a pretty good look and feel of how the new area works. We'll know more when larger summer crowds start to offer a better stress test, but for now I like the look better than I thought I would. You can see for yourself with these images.
This is the sort of image that we'll never see again with the new Hub, as the old docks/load/unload areas for the Swan Boats are gone.
Seeing a view like this made me feel a little better that there are still attractive water vistas to be found
One benefit of the new construction is a larger seating area outside the Plaza Ice Cream Parlor
A look into the new fireworks FastPass+ viewing area
A similar fenced in area to what is currently being used for FastPass+ viewing is also present on the opposite side of Main Street (near the Plaza Restaurant), though at the time of my visit it was not being used for FastPass+ fireworks viewing
New fountains have appeared
The mini statues that used to surround Partners have been moved (out of arms length)
Walt is still around to watch over the park
The fireworks viewing area drew crowds, but not nearly as densely packed as those elsewhere in the park. On the night I attended, most guest chose to sit on the fake grass (I setup my tripod in front of a tree, so as not to block anyone's view of the show).
I saw more of Celebrate the Magic than I ever have farther back on Main Street, managing to find a spot with no heads blocking my view
Wishes looked good, too, though I'll note there are quite a few lighting fixtures blocking many of the views in the FastPass+ viewing area. I arrived early and made a point to station myself somewhere that offered an unobstructed view of Cinderella Castle
This should give guests an idea what the expect next time you visit the new Magic Kingdom Hub, but let me know if you have any questions.