The upcoming "Princess Cadance and the Glitter Heart Garden" is now listed on Amazon for a new cover. It also has an updated description:
Princess Cadance is determined to bring love back to Equestria. But when she creates the Glitter Heart Garden, the plants have a rather unusual effect on the ponies... Can she and her pony friends fix everything and bring happiness back to the kingdom?
Expect it to be officially available on the 12th of January. Unfortunately pre-orders don't look to be up yet.