In medeival times a mount was commerade and partner to a knight as much as a pet is to a hunter in the game, being able to tame a mount would allow the hunter the choice of what kind of mount they get, which in turn would promote their emotional attachment. Size would not be an issue as most times when you tame a pet they shrink in size but their original size is appropriate to Mounts. I am not suggesting that all tameable animals be made tameable as mount, but obviously there would be certain ones that could be and others that couldn't.
I like the idea of having different Hunter trainers being able to train you to tame different mounts. In Darnassus there would be a trainer who could teach you to tame a Cat, in Orgrimmar you could be taught to tame a Raptor or Wolf, in IF a Bear or Ram etc.. If you wished to ride a cross-faction mount maybe Ratchet and Booty bay would have trainers for cross-faction mounts so that a NE could tame a raptor or an Orc could tame a cat.
Here is a list of my ideas for potential Mounts for Hunters:
Cats- From Nightsabers to Lions and Tigers
Wolves - Most wolves that I have seen are all the same
Hyenas - kinda cool evil looking mounts for hord
Zebras - I know that in-game they are called something else...
Thunder? - forget the full name, but they kinda look like Kodos
Kodos - great for the Taurens
Wild Mustangs - this would actually require an addition to the beast list
Rams - found in the Northern Pass
Bears - Great Mounts for Dwarves
Giraph - from blasted lands - not right name, but you know what I mean
Raptors - there are many larger raptors that would be fine for this
Spiders - some of the larger spiders could easially be made into mounts if the game did not shrink them. Imagine riding Lady Sathrah around.
I would even go so far as to say that if you want a mount that is already a mount for a certain race you would have to buy it, and the only animals that would be tameable for this purpose would be those that are not available to your faction (a stretch) or ones that are not currently available for purchase.
As for price, I don't know how expensive it is to learn to summon a mount for the other classes, or how much work the quests involve, but similar pricing could be developed for hunters to keep it fair. You wouldn't be able to just go pay 10s and get trained to tame any available beast as a mount or anything. Perhaps a quest which takes you through the ringer to prove that you are worthy and then a cost for the training comparable to that of the Warlocks and the Pallys.
I am developing a website where people can add their information to a list asking Blizzard to add this to the game. I plan on adding all reasonable limitations and ideas to the request, so if you have any details that you think should be a consideration, I will review and if they have merit add them to the final proposal to Blizzard.
If anyone has experience in creating the graphics or any technical information so that we can anticipate what Blizzard would have to do to accomodate us it would be helpful if you could provide constructive comments. The more we know about what they have to do to make this happen the more likely we would be to give them a proposal that would be feasable for them.
Stay tuned to find out more about the website/petition. I hope to post a link to the page as soon as it is available.