It is rolled out for TW, HK, WWE, RU..
Left Starhub ( singapore) firmware not rolled out yet.
The information provided earlier was not accurate.
You can flash original jelly bean firmware from Asus without root.
ASUS - Mobile- ASUS PadFone 2
Of cos for now you have to flash other country's firmware.
Personally i am on TW 10.4.7.10.
TW firmware always get the latest and fastest updates.
A word of caution though, once you flash other firmwares, you will not be able to get OTA updates, but you can update it manually.
A few pages back i posted a step by step guide.
For change of SKU to TW firmware, you might need to flash twice.
first time for re-partition. ( still on old firmware)
Second time for the replacement of /system files ( actual flash )