From Cycle World Website:
Did we complain about the cheap-feeling suspension on the original FZ8 two years ago? Yes, we did, particularly its under-damped shock. For 2013, Yamaha addresses that concern by bolting on a rebound-adjustable shock wrapped in a stiffer spring. Up front, the inverted fork now lets you play with spring preload as well as compression and rebound damping.
A new muffler with brushed-aluminum-looking end cap and trim gives a more upscale look, while a new seat cover with a grippy top texture and faux suede side panels does the same. Sticker price is up $200, to $8890. Available in Matte Gray or Matte Black this coming February.
This is all I have found so far...