Its hard for new players and mid-level players to get around because they don't have a permanent mount, but why not make it so their own pets can be used as mounts? Not all pets can be ride-able because they wouldn't make any sense, for example you can't ride things like the Enchanted Armament or the Ghouls. It would be up to Kingsisle's judgement to determine what pets can be ride-able. Your pet would have to be a certain rank in order for it to be ride-able, like with the pet jewel sockets. The higher your pet's rank and stats, the faster the pet can be as a mount. In order to even ride the pet, you would need to obtain a Saddle, which can be dropped by certain bosses or be crafted in Exalted Crafting / Promethean Crafting. As pets are, they don't look like they could be ride-able since they're so small compared to the Wizards, so the pets can use their own magic in order to grow to a certain size to be ride-able.
This idea was brought up due to there being pets that are already found as mounts. (Hydra, Treant, Lions, Sabertooth, etc.)