When this patch hits .. two new races appear .. the Kul Tirans and the Zandalari. They will be rep-gated .. but it should be fairly easy to gain this rep (most may well already have it) .. with, for horde meaning you need to be exalted with the Zandalari. You will also need to have completed the War Campaign quests and completed the achievement Zandalar Forever!. Zandalari druids look awesome!!
Along with the new races, we get new Portal rooms. For the horde this is located inside the Gates of Orgrimmar, just before entering the Valley of Strength. More compact than its Alliance counterpart, it favors much more Horde inspired decor.
It also contains portals to seven major cities across each expansion, excluding Cataclysm, with the Jade Forest portal taking players to Honeydew Village and Azsuna to the Court of Farondis. There is also a Thrallmar Mage who will send you to the Blasted Lands upon request.
More information regarding the portals, and portals that have been removed, can be viewed here.
Additionally, for those altoholics amongst us, there has been a change to how many characters you can have per realm .. which has now been changed to "all of them" :p The maximum characters on your account has not changed, and is still 50, but now you can have as many as you want, anywhere, up to that limit.
Yeah .. and I've seen a lot of complaints about the portals too .. apparently they removed a lot more portals than they're putting back. Time will tell. A lot were complaining about the Dalaran portal ... but most will have a Dalaran HS anyway .. unless I misunderstood.