Avengers: Age of Ultron - Casting the VFX Vendors
fxguide have created a very thorough article about the VFX vendors contributing to the massive Avengers: Age of Ultron.
Behind the Magic: The VFX of Captain America: The Winter Soldier
Industrial Light & Magic go behind the magic on the VFX for Captain America: The Winter Soldier.
Blur: Thor: The Dark World VFX Breakdown
Blur Studio have posted a VFX breakdown of their work on Thor: The Dark World.