the PAM422 is basically the PAM372 + sub-second + PR indicator at the back
the PAM423 is then = PAM422 with PR indicator in front
all based on the new P3000 movement.
I spoke to a couple of boutiques and they are expecting this model to hit the boutiques in the next 3-4 months as the first 2012 lineup. So you can expect them to hit our shores via grey networks by September or so.
As for authorised networks, maybe a few months after that.
The RRP for 372 is RM33800
The PAM422 will be about RM35k
and the PAM423 will be 300RM more than the PAM422, which is usually the case.