I know I'm a little late to add to this discussion, but I am attaching the info for several articles that discuss mobilization in the ICU.
-Milbrandt EB. One small step for man ...Crit Care Med. 2007; 35:311-2.
-HopkinsRO, Spuhler VJ, Thomsen GE. Transforming ICU Culture to Facilitate Mobility. Critical Care Clinics 2007. Vol. 23. Issue 1. 81-96
-Perme C, Chandrashekar R. Early Mobility and Walking Program for Patients in the Intensive Care Unit: Creating a Standard of Care. American Journal of Critical Care. 2009
-Dean E. Mobilizing patients in the ICU: Evidence and Principles of Practice. Acute Care Perspectives. Spring 2008, Vol 17, Number 1, 1-9
I hope this helps. I have worked in ICU's where aggressive mobilization is a rarity, and other hospitals where it is the norm. There is no comparison- patients do much better when early and consistent mobility is facilitated in the ICU.