I visited the Cataclysm Preview Panel this morning after the Opening Ceremony and I have a rundown for you after the jump.

• Chris mentioned they have learned from The Burning Crusade and wanted the boss to be ever present while leveling like they did with Arthas in Wrath of the Lich King. So you know who the big bad guy actually is.
• Deathwing - One of the Five Dragon Aspects - The Earth Warden
  • He has been driven mad by the whispers of the old gods.
  • His power was unleashed and now needs plates strapped to him to even keep him together.
  • Chris Metzen calls him a nutcase.
  • Old gods whispers made Deathwing worse and he ripped a hole into Azeroth from his plane of Deepholme.
  • His eruption from deep within the Eastern Kingdoms caused the entire world to be forever changed.
  • Elemental Planes
    • Titans had banished the elementals who ruled the world pre-current Azeroth.
    • They are really pissed and you will see the return of Ragnaros.
• Worgen
  • Greymane Wall was closed off as Dalaran fell to the might of the Scourge.
  • Dalaran wizard named Arugal summoned something much like our current worgen.
  • This was the source of the curse.
  • Starting zones will help show you how the people of Gilneas became cursed and their story.
  • Scythe of Elune story line will be involved.
  • Are they from somewhere or some-when?
  • They are meant to be like the Wolverine of the Alliance.
  • Lots of unique things in the starting zone with heavy usage of the phasing system much like the Death Knight starting zone.
• Goblins
  • From Kezan
  • Completely seperate from the Steamwheedle Cartel
  • Very technological
  • They are neutral to the Horde at the start of leveling and during the starting zones you will find out why they joined the Horde.
  • Kezan was hit very hard.
  • Driven out and shipwrecked on the Lost Islands.
• Lots of Wrathgate like cinematics.
• The Horde might need the comic relief of the Goblins.
• Dark Days will be ahead.
• The Horde and Alliance will be tested.
• Upheaval
  • Tidal waves, tsunamis, heavy storms, volcanoes tear the world apart.
  • New stress between the Horde and Alliance.
  • Lich King had lured us to Northrend and screwed with our minds.
  • The Lich King gets what he deserves.
  • We might not be bringing something back with us?
  • The world is not what it once was.
  • Lost a lot of Horde vs Alliance in Outland, wanted more division that could be seen and refreshed.
  • Bring the War back into Warcraft.
• New Features
  • Level Cap is 85
  • Focus time and energy in the right places.
  • Mainly to allow time for the zone revamps and lots of new content.
  • Worgen's get a sprint like racial ability.
  • Goblins get a rocket belt that works like a reverse disengage or shoot rockets at players/npcs.
  • Seven new zones PLUS the revamped zones.
    • Mount Hyjal
    • Uldum
    • Sunken City of Vashj'ir - The Underwater zone
    • The Lost Isles
    • Gilneas
    • Twighlight Highlands
    • Deepholme - Elemental Plane of Earth
    • The scar left in Eastern Kingdom from Deathwing's eruption into the world has created an entryway into Deepholme.
  • Guild Advancement System
    • 20 levels for guilds
    • Leveling up gives you perks and talents
    • An example of one guild talent is Mass Resurrection.
    • Leveling up can be done by everything you already do like raiding, doing dailies, battlegrounds.
  • New Class/Race combos
    • HOLY COW - Tauren Paladin
    • Dwarf Shaman
    • Gnome Priest
    • ...and more
  • Phased Terrian to allow the world to physically change as you progress.
  • New Secondary Skill: Archaeology
    • Get access to nodes and research new Path of the Titans.
  • Path of the Titans
    • A new alternate way to advance your abilities.
    • Makes me think of EQ's AA system.
    • No new talents but 5 more points to spend.
  • Mastery System
    • The more points you spend in a tree the more you master it.
    • Gives things such as more damage and stuff that was merged into talents.
    • Allows you to take more fun and interesting talents instead of everything that boosts you.
• The World
  • Cataclysm on Azeroth reveals new lands and changes old favourites forever.
  • 5 new zones for 78-85
  • New leveling flow for 1-60
  • Two starting zones for 1-15
  • You can fly EVRYWHERE!
  • Multiple levels of change.
    • The Barrens has been sundered in half and is now two zones.
    • Alliance has finally lost Southshore.
    • Desolace is now green and revitalized.
    • Fix Darkshore and less of a pain to travel
    • Zoram Strand is now larger Horde base in Ashenvale.
    • Stonetalon now has a new Goblin base and they cut a wall right into Ashenvale.
    • Ashzara is now a 10-20 zone for Goblins.
    • All major cities have been revamped to allow flying in all of them.
    • 78-85 leveling path
    • 78-82 Sunken City and Mount Hyjal
    • Deepholme is the hub zone similar to Dragonblight
    • Uldum and Twightlight Highlands will be where you hit 85.
    • Vashj'ir is underwater on the sea floor.
      • Finally came to life with the Cataclysm.
      • Abysall Maw Vortex leads to the Water Elemental Plane with 2 new dungeons.
      • Will play like on land when you are on the floor and you'll be able to just swim up.
      • Underwater mounts will be the speed of flying mounts.
    • Deepholme
      • Was not really connected to Azeroth until Deathwing broke through.
      • It is the Earth Elemental Plane.
      • Biggest zone in the expansion.
      • Twighlight Hammer nursed Deathwing back to health here.
      • It will be the hub zone of the expansion with portals to the other new zones.
    • Uldum
      • Ideas taken from Egypt
      • Cataclysm destroyed the Titan machine that held everyone from being able to enter it.
      • Brann will most likely be there.
      • Rumoured to hold a super weapon.
      • Home of the creatures Tol'vir
    • Mount Hyjal
      • Under siege by Ragnaros
      • Sent his army to burn the World Tree.
      • We basically banished him back to the fire elemental plane when we killed him in Molten Core.
      • Malfurion is back and he's pissed and helps protect the world tree.
      • Darkwhisper Gorge is now part of Hyjal and is occupied by Twighlight Hammer.
    • Twighlight Highlands
      • Grim Batol was sheared in half by Deathwing.
      • Headquarters of the Twighlight Hammer.
      • Two port towns located here.
      • Red Dragons pushed back but their base is here.
      • The new Twilight Dragonflight is here.
    • New Dungeons
      • The Firelands - Home of Ragnaros and Sulfurion Keep
      • Uldum - Halls of Origination and a city of the Tol'vir
      • Blackrock Caverns - Brand new dungeon in Blackrock Spire - lots of Twighlight experiments
      • Grim Batol will have a new dugeon and raid.
      • Skywall will have a dungeon and raid also.
      • HEROIC Deadmines and Shadowfang Keep.
• PvP Preview
  • Tol Barad - New PVP zone
    • Off the Coast of Eastern Kingdoms
    • A prison is located here.
    • Sits on an island.
    • Both Horde and Alliance want control of it.
    • Melding Wintergrasp and Quel'Danas
    • Win and get bonus daily quests to do.
  • New BG: Battle for Gilneas
  • Hope for 3 new BGs total.
  • New Arena Maps
  • Rated Battlegrounds