Cataclysm Progression Timeline (Release)
Patch 4.0.3a released → 23rd November, 2010 (The Shattering)
Cataclysm released → 7th December, 2010
Throne of the Four Winds (10) → 
Ouroboros → 27th December, 2010- The Bastion of Twilight (10) →
Ouroboros → 9th January, 2011 - The Bastion of Twilight (25) → Ouroboros → 18th January, 2011
- Blackwing Descent (25) → Ouroboros → 28th January, 2011
- Blackwing Descent (10) → Exile → 6th February, 2011
Patch 4.0.6 released → 8th February, 2011
Patch 4.0.6a released → 11th February, 2011
- Throne of the Four Winds (25) → Dream Team → 13th April, 2010