A really nice collection of tiles.
The pack is missing a few things which would be useful for both you and the final user:
* A license .txt within the pack
* Your username attached some way to the pack, either as the title of the zip or within the license (or both).
* A link back to your project.
The license is always an encouraging part of the pack. If, like me, people are downloading the pack for future use, they'll want to know what terms they can use the assets under. Likewise if you put your username on it it helps with knowing who to credit. Last of all it's really useful for people who use your art to know where they can come back to and donate if the assets proved useful.
A final improvement would be an inspiration image to indicate how the tiles can be used. I'd recommend mocking something up in tiled for your terrain tiles.
Just my two cents!
-PD