WoW Forever changed how you pay for a mount: the cost has moved into riding training, and you're given a mount when you learn the skill. That's Confirmed from Blizzard's panel recap, which describes it as the Burning Crusade-style approach. There are no flying mounts either, per Blizzard's What's Next recap.
What level and how much
Blizzard hasn't published the riding level or price on any page we've read.
Unverified, from players:
- One forum post gives Apprentice Riding at level 40 for 100 gold, and Journeyman Riding at 60 for 1,000 gold.
- Other beta threads also refer to level 40, and players are asking for it earlier.
Treat those prices as a rough guide until someone has paid them on live.
Saving up
Blizzard's only published cost is class training: between 206 and 207 gold for all abilities from 1 to 60. That's on top of riding, as far as we can tell. So if those riding prices hold, 100 gold at 40 competes with your training bill. Two gathering professions are the simple answer. See making gold while leveling.
The Heroic Pack mount
Confirmed: the Skyborne Heroic Pack includes the Cerulean Prideclaw ground mount, but Blizzard's pre-purchase post says you still need to buy the riding skill in game to use it. So the mount doesn't let you ride early.
Other mounts we can confirm
- PvP: rank 11 unlocks mounts (PvP post).
- Legacy: Reins of the Spectral Bear is a Legacy reward, as a cosmetic (Legacy post).
Blizzard's notes don't list faction or racial mounts in what we've read. Unknown.
Things that affect your speed
- Tauren's Plainsrunning no longer raises mounted speed since 3 November, and it now gives up to 60% on foot (notes).
- Druids have Travel Form, and Blizzard's list of Skyborne forms is separate.
- Blizzard's Legacy perk Frequent Flier makes flights cheaper and faster.
Warlock and Paladin mounts
Class mounts come up on the forums, with players disagreeing on how they work. Unknown for now, so check your class trainer. See your class guide for what else you'll be training at that level.