Of all the changes made to the levelling experience over the last year or so, the one that has had probably the most effect on me is the changes to the level and financial requirements for riding training. Back along (in the day yada yada yada) intial riding training was at level 40, epic at level 60, initial flying at level 70 and the further epic flying also at 70. Training was pricey, mounts were pricey and my first character to level 70 didn't get epic flying until Northrend and probably level 80. And non epic flying was slooooow. None of this 150% speed increase like now.
I recall when initial riding training was lowered to level 30 and reactions were mixed but favourable in the main. Then it dropped to 20, speedy at 40, flying at 60 in Outlands, epic still at 70 and having to wait til 77 to purchase cold weather flying. Now (in Northrend) you buy a book on your main and send it to your alt and fly pretty much from the get go. I think it's fair to say that reactions have been mixed to all these 'riding buffs/nerfs'. From the point of view of someone who runs multiple characters it's a massive advantage. Some of the vanilla WoW zones are huge (I'm looking at you Ashenvale, and you Stranglethorn) and running all over them was... well, I used to refer to Ashenvale as the 'sink of despair', enough said? In addition, Northrend spoilt me by having a lot more flight paths than I was used to, i.e. a lot more than the Old World has.
Now even by my fairly slow levelling standard getting to 20 doesn't take very long. At all. And no matter how many times I do it, I still get a little leap of glee when I first get a mount. It does improve the levelling experience. Flying from the get go in Outlands I'm not so sure about. Oh, don't get me wrong, I take the option. In fact moments (well an hour or so) ago I took Eskie to Thrallmar and bought myself a windrider. Training cost me 225 gold; I'm guessing I got a faction discount, amusing in itself as less than a week ago the Guards in Orgrimmar were hurling rotten bananas at me, making me smell delightful and the mount then cost me 50 gold. So less than 300 gold for the ability to zoom around Outland. Cool huh? Well yeah, kind of. Outland is special to me. Probably due to it being the first expansion, all the people I met while questing and instancing there and for multiple other reasons. And yes, flying round it is quicker, not having to carve my way through mobs is also (probably) a bonus. I've just spent a happy hour flying round picking herbs (last... few... alchemy... skillups... hurt) and it was a breeze. Maybe I'm suffering from inappropriate nostalgia as I'm failing to nail what it is about it I dislike. I'm sure when I take Mishe there she will also get flying straight away. As will the others. Much better really than having to level uphill, backwards, in the snow, barefoot...!