Calling WorldGate HQ, a very convincing demo. The framerate was 30fps, quite snappy. The clap-test showed perfect sync between picture and sound. Latency was not perceptible.
The image resolution is QCIF (176x144), allowing 30fps using a mere 110kbps, just right for the majority of ADSL users with 128kbps upstram. The framerate makes the call very natural, despite the low resolution.
All in all, an awesome phone. All the better that it supports SIP.