I think you are right. It does look like a 4 pin firewire port. Here's a close up from the Chinese flash presentation: http://www.angelfire.com
/un/deltawalkerl/SpecialR.jpg (I flipped the pic horizontally so it's the right orientation and erased the text)
But the FireWire port should be on the left side rather than the right:
So I think there are two possibilities: either there are two variants of the W1 (probably due to the TV tuner option), one has one FireWire port and the other has two FireWire ports. Or that the model with the FireWire on the right side of the notebook is an earlier prototype, and that Asus has since moved the FireWire port to the left side. I do vaguely remember seeing a model with three USB ports on the left side...