Yes, there are definitely changes to what happens with the horse in 1.6.
1) Each type of horse you own turns into a collectible skin you can activate. It will be in the collectibles - Press U to find it and go to mounts. NOTE: You will not have a mount active when you first log in on 1.6 and will have to pick one to activate it. It will not matter which horse is activated, all Riding Skill stats will stay the same. Type of horse is for looks only!
2) All stats of all horses on one character will combine into one pool for your Riding Skill. The max is 60 for each stat. EXAMPLE: If your currently own three horses and just had the standard or Imperial horse and all are maxed on one stat you will have 50/50/50 across the board for your riding skill upon entering 1.6. You will be able to add 10 more points to each stat - one every 20 hours for 250g. The cost and time for adding a skill is the only thing that has not changed.
So how to max out your horse before 1.6. Have three horses leveling the different stats and work on feeding all three every day to get them as maxed as you can before 1.6 goes live. If you PvE/PvP regularly you probably have one if not two of the stats already maxed at 50 for a generic/Imperial horse. Work on at least getting all three to 50 on the standard or Imperial horse as best you can. If you have one of the special horses before 1.6 you have the chance to max to 60 ahead of time. I suggest working on this now because in 1.5 you can up 3 stats a day across your horses. In 1.6 you can only up one stat per day no matter how many horse types you own!
