What you will see in patch 5.0.4
These are the changes that will happen on Aug. 28 with the 5.0.4 patch.
■ Account-wide achievements, pets and mounts (account-wide system does not include reputation)
■ AoE looting
■ BattleTag support
■ Class and talent system changes
■ Item changes (head enchants, relics, and ranged and thrown items are gone; spell pen has been replaced by the new PvP power stat)
■ Profession changes (only glyph changes)
■ UI changes
■ World Event: Attack on Theramore Isle
■ Currency conversion
What will not be included in patch 5.0.4
These things will not be included in the patch.
■ Pet battles
■ Pandaren characters
■ New/heroic dungeons
"Anything else that is not in the official patch notes will not be included with patch 5.0.4. Basically, patch 5.0.4 is simply putting in new UI, system and class changes, along with a world event. Everything else will be available once Mists of Pandaria launches in September."
■ World of Warcraft PTR Patch 5.0.4 Notes - http://us.battle.net/wow/en/blog/6761563
■ 5.0.4 Survival Guide by Bashiok Aug 24, 2012 - http://us.battle.net/wow/en/blog/7045643
■ Currency Conversion Before and After Mists of Pandaria by Blizzard Entertainment Aug 24, 2012 - http://us.battle.net/wow/en/blog/7029341