As I figured, the new flying machines for Engineering have caused quite a stir. I finally got my engineer copied to the PTR yesterday and she went out to Shadowmoon Valley to find out what components were required to make them.
They've added a new Engineering trainer to Wildhammer Stronghold, she's located by the Forge and her name is Niobe Whizzlespark. Here is a picture of the mat requirements, bear in mind that these could be changed between now and the release of 2.3 (click to see full size image):
The cost to learn the regular flying machine is 11.4 gold and the cost of the turbo-charged flyer is 17.10 gold. Cheap - but of course the bulk of the expense will be in the ingredients and not the recipe. You should also note that the turbo version requires the basic version as an ingredient. Those of you with epic mounts already will not be able to jump straight to the turbo flyer unfortunately.
The part that I find rather unfortunate here is that the basic model requires Elemental Seaforium charges, which can only be learned by achieving Revered status with the Consortium. This is not a faction that players typically work on unless they are a Jewelcrafter or a rogue and there's not much in the way of dungeons you can run to increase it. The only dungeon options are Mana Tombs to Honored and Heroic Mana Tombs through Exalted. Getting the key to Heroic MT requires Revered reputation with the Lower City, another low priority faction for most people. I guess we'll find out how much of a stumbling block this turns out to be... I suspect the Engineers who do have it will end up creating a market for those who don't.