Ford officially replies to the NHTSA regarding Mustang transmission issues:

http://www-odi.nhtsa.dot.gov/acms/do...024-48900P.pdf

In terms of changes made since the 2011 production began:

04/26/2010: Revised Clutch Pedal Return Spring
For clutch stay-out at high RPMs

01/07/2011: Revised Clutch Spring Finger Height
For clutch stay-out at high RPMs

10/19/2010: Revised fastener/thread locker
Addresses clutch fastener back out

09/07/2010: Changed 5th/6th gear surface finish
Addresses grinding during 5th gear shifts

07/25/2011: Added phosphate coating to gears
Reduces gear noise

07/25/2011: Lower viscosity lubricant
To reduce shift effort in all temps

08/31/2011: Changed clearance between 2nd gear friction ring & cone
Resolve ring to gear face contact and gear clash

02/25/2011: Fourth gear weld incomplete during production
Process verification to ensure complete gear welding

07/01/2011: Vehicle message center
Extended skip-shift illumination time so drivers aware of engagement

 

They do..but also..look at that list. Inadequate fasteners, skip shift bugs, various synchro/gear quality issues...