Came across these articles online last week and thought I would share them for anyone who hasn't had the pleasure of reading them.
Discussion with Aaron Weintraub (VFX Supervisor at Mr. X)
http://www.artofvfx.com/?p=758
Discussion with Chris Harvey (VFX Supervisor at Prime Focus)
http://www.artofvfx.com/?p=885
Discussion with Danny Yount (Creative Director at Prologue Films)
http://www.artofvfx.com/?p=768