Slightly OT, but also along the line of "professions":
Ever wondered why Blizzard was suddenly so "generous" to give players access to the whole palette of finest elite mounts for just 100g each (90g with faction bonus) in patch 1.12.1?
Well, here's the answer why:

If you look closely to the new riding professions, which are now the costly part of your improved mobility, you'll note that riding an elite mount not only requires character level 60 but also the previous profession stage, "Riding (75)" or "Apprentice Riding" in this case.
That means that you cannot simply buy cheap riding for 20 gold anymore, and skip expensive mounts (as ist was well possible in patch 1.12.0), but that you MUST buy each and every riding stage for much gold to climb up the ladder further.
In "The Burning Crusade", we'll see Netherdragon mounts and Elite Netherdragon mounts. The next skill stages could therefore look like this:
QUOTE
Expert Riding
Requires: Level 65, Riding (150)
Cost: 2000 Gold
Allows the player to ride basic air mounts that require a riding skill of 225
Artisan Riding
Requires: Level 70, Riding (225)
Cost: 5000 Gold
Allows the player to ride swift air mounts that require a riding skill of 300
So, in order to ride an Elite Netherdragon, you'll pay since patch 1.12.1:
90g + 900g + 2000g + 5000g = 7990g
and not 20g like before in patch 1.12.0.
2000g and 5000g for air mount riding are currently just speculation on my part, but a pretty astronomical sum of gold (read: huge time sink) is certainly guaranteed