This prompted a response from Zarhym [a Blizzard forum mod, iirc] 'Allowing players to purchase and ride mounts at level 30 does not at all diminish your prior accomplishments in my eye sockets, Ithnin' This was followed by a post explaining that new players may get their mounts ten levels sooner, but they have ten and soon twenty more levels to go through before they reach the endgame. The majority of responses in this thread are supportive of the change.
I'll disagree, as you might have guessed already from my Take the Nether off the AH post. It's easier to level with a mount. That's why we all buy them. The world contracts when you've got a way of getting places 60% or 100% more quickly, and that means it takes less time to to whatever it is your character needs to do.
To level a new character, you still, generally speaking, have to pass through the same content to get your experience as you did when WoW was first released. Now Duskwood, one of the more memorable zones in my leveling below 40, will have all sorts of folk riding through at breakneck speed. That makes Duskwood easier, and cheapens the time I spent there, and I was there a while.
(And if memory serves (it might not), haven't the experience requirements for leveling already been cut considerably? Certainly attunement's been shut down, which stinks.)
But here's my main gripe: Blizzard had already found a way to make leveling easier for your alt characters. It's called starting your Death Knight at level 55. My highest level alt is level seven. I don't care much for the lower levels. I'll certainly be giving a Death Knight a shot, though, even though they sound like a moonkin-like hybrid (non-squishing magic using tankable) in many respects. A Death Knight is already going to be powerful enough to run the content I remember enjoying. Heck, if you just start me off strong enough to adventure in Duskwood, I'd probably play alts more.
Does the Death Knight cheapen the game? Arguably yes, but in a much different way than making mounts cheaper and more available or reducing XP needed to level. Now experienced players can create a special class of alt char that doesn't have to lowbie grind. We've solved the problem that Blizzard must have seen when BC came out. Sure, Blood Elves and Draenei are k3wl, but I didn't have much fun blasting mana eels or whatever they were for 7 hp a pop. The Blood Elf starting levels looked spectacular, but I couldn't leave them and quickly got tired of snarking around -- and heck, my main saw the same architecture in Outland. Many other veterans must have been similarly unimpressed with the new alt experience. Okay, Death Knight in and problem (hopefully) solved.
So the main reason to make lowbie leveling easier, imo, must be to get new players involved more quickly. This suggests that the endgame (and near endgame) content must be much more enjoyable than the lower level questing to new players. Is the motivation that if you can get players new to WoW to endgame quicker, they're more likely to stay and keep paying?
Instead of cheapening lower levels by playing god with leveling economics, why not do like you did with the Death Knight -- put in the development time and change the game. Put in instances for level 5 characters, perhaps. Have lowbie PvP battlegrounds. Allow people to level in PvP until level 30 or some such. Now traditional leveling is still an option, but you've got the flash that's needed to keep some of your new revenue stre... ur, players.
If you don't simply introduce new routes in the same vein for leveling lowbies but instead starkly change the lowbie game experience, you might find more veterans starting over too.