First, there will be a new zeppelin route between Thunder Bluff and Orgrimmar. We heard about this before, but now we know in what patch / context it will be released in.
Secondly, there will be portal in Stormwind and Orgrimmar leading directly to the Stair of Destiny at the Dark Portal. No more need to haul yourself out there at level 58. Just take a portal instead!
The portal in particular should help people level in Outland much easier. It should also help to significantly decrease the use of Hearthstones for traveling back and forth between Outland and Azeroth. Now you can fly to Shat in your 150% flying mount at 60, take a portal to Stormwind to train, and then portal right back to the entrance to Outland where you can hop on your flying mount again and return to grinding levels. Very quick, very easy, very smooth.