ASUS confirms it's working on Android 4.2 update8
ASUS has always been quick on updates because it doesn't add much to the stock Android experience. Not surprisingly, the Transformer Prime TF201 is expected to get the update first, and ASUS seems to have said the tablet will get the update "soon".
That was the only specific tablet mentioned, but ASUS has confirmed that it is working on the update for all of its tablets.
source: Planet Android (NL) via Droid Life