As per http://avrupgrades.denon.com/
"WHAT IS INCLUDED IN THIS UPGRADE?
• Latest Sound Enhancement with:
Audyssey MultEQ XT 32—32 times the resolution of MultEQ XT
Audyssey DSX—Availability of Height or Width effect speakers
New Audyssey Calibration Microphone
dts Neo:X—Availability of Height or Width effect speakers
Dolby PLIIz—Availablity of Height effect speakers
Subwoofer Level Matching—Allows for proper level matching of multiple subs before Audyssey calibration
• HDMI 3D Pass through
Allows for 3D video pass through on the all HDMI inputs and output.
• Denon Link 4th
For AVR5308/AVPA1HDCI that did not get previous firmware update.
• A Full firmware update service is performed
This ensures the unit is completely up to date and running properly."
Denon says that the upgrade is supposed to cost $999.99, not $1100.00, however that is not including any taxes that there may be you your area.