Is it overhyped?
Yes and no
Its just a step in a surtain direction.
A lot of people complaining about that WP is not customizable.
MS made it possible, at first with the tiles lateron they started with the wallpapers.
And now with the lockscreens.
This is just a beta example, to show people and developers wat is possible in the new os.
Is it nice or gimmick ....yes, for clean functionality you dont need it, you don't even need a wallpaper or resizable tiles.
Its just a answer from MS to its users.
No one is forcing anybody to use it, its just a way to personalize your phone.
I think its a good thing.