Bornakk commented at a forum topic related to the cost of the flying machine cost. It was hinted that on Wrath of the Lich King expansion there “might” be a new riding skill. It could be speculated that to be able to fly in Northrend near level 78-80 a riding skill will be needed to learn to fly under the icy, cold conditions. Either that, or there are new and faster mounts we haven’t heard of.
Bornakk: We are planning to make it a 280% speed mount, so it will require 300 riding skill just like the other epic flying mounts.
And yes, we have no current plans to lower the cost of 5000 gold to get 300 riding skill before the expansion though this may be revaluated at some point in the future like when a new riding skill tier is implemented.