Crown shop mounts have become common and worn out, I suggest school mounts. At level 50, people can get a free school mount from a quest given to them by their teacher. These mounts all have 5% power pip chance and 50% speed increase.
For the mounts i was thinking they should be related to the school making them more exciting and another thing to look forward to when you max out an account.
Fire : Fire Hound, Ice : Ice Wyvern, Storm : Kraken, Balance : Oni, Life : Centraur, Death : Skeletal Hound, and Myth : Orthurus.
These are just some ideas for the mounts I figured would fit each school.