So the firmware now allows 6 rather than 3 simultaneous effects, and has added a load of fx and amp models, as well as the ability to turn the auto-save feature off (defaults off) The new amp models (apparently) are:
Fender Deluxe Reverb(DELUXE-R), Early Vox(VX-JMI), Carr Mercury(CAR-DRIVE), Sound City 50 mkII(TONE-CITY), Blues Breaker(B-BREAKER), 1959 Plexi(MS 1959), Bogner Ecstasy ch3(BGN DRIVE), ENGL Invader(ALIEN), Krank Revolution 1 plus(REVO-1)
I've not had chance to have a proper look to see what stomps have been added.
Also, for Edit and Share to work after the firmware update, you need to update Edit and Share to v5.0, also on the Zoom's japanese website.
And another thing: if you have patches saved into your unit taht you want to keep, back them up before doing the update, as this will wipe your patches!