Not having an upgrade path for the thousands of customers who use appliances seems very short sighted. I would be very dissapointed with Astaro if this turns out to be the case.
I am not sure about the appliance testing, but they have had V7 running on a 120 and if you view the demo now it is running on an 525 appliance. So
for testing I would assume there is some way to try it out.
The 120 and 525 appliances have VGA connectors on the back of the device, so the software version can be installed interactively. The rest of the appliances don't, so there's no way to run the install on these appliances until it's released through up2date.