That will only have 128GB of unified memory

128GB for 3K; per the announcement their ConnectX networking allows two Project Digits devices to be plugged into eachother and work together as one device giving you 256GB for $6k, and, AFAIK, existing frameworks can split models across devices, as well, hence, presumably, the upthread suggestion that Project Digits would provide 512GB for $12k, though arguably the last step is cheating.

the reason Nvidia only talk about two machines over the network is I think they only have one network port, so you need to add costs for a switch.

If you want to split tensorwise yes. Layerwise splits could go over Ethernet.

I would be interested to see how feasible hybrid approaches would be, e.g. connect each pair up directly via ConnectX and then connect the sets together via Ethernet.

It clearly have two ports. Just watch on the right side of the picture:

https://www.storagereview.com/wp-content/uploads/2025/01/Sto...

You will however get half of the bandwidth and a lot more latency if you have to go through multiple systems.

Apple is shipping today. No future promises.