The OpenSuSE 12.3 issue with the slow network start-up time seems to be some timing issue. It might be because two processes start the network at the same time. One being auto plug and the other the network start time. I was looking into it until it suddenly stopped happening, so I stopped looking into it.
The next problem was/is that packer does not always reconnect to the install after the reboot. that might be related to the network issue or not. But the odd thing is that it worked once with a two hour period of successful sshd polling and the next time it failed after one minute of failed polling. did change my script from being in the background with nohup (to work around the udev network issue) in between, but I am not sure if that is related. started to check in the changes in to the https://bitbucket.org/markus_ebenhoeh/packer-opensuse.12.3 repository to track what I am doing.