Same here, running insulated ductwork through the un-insulated attic is normal. But don't get me started on insulation. I'm not from around here, and from what I see in our home and others makes me think that if people would invest $10k more building the house, they'd save multiple of that during the lifetime of the home. Making the outside walls 12" thick (it's just framework) and filling them with insulation goes a long way and is not really expensive. Insulating the attic may be a different story.
But back to the point, the most losses you have from a forced-air system are air losses by faulty seals, and not the heat loss through the duct. So if your HVAC builders do a good job there, that really helps.
@Bad LP: I don't really see the issue of servicing equipment up in the attic. There's floor boards around the units and leading to them, and there's space around them, so it's actually easier to service compared to a unit in a closet. Sure it gets hot in Summer up there, but HVAC service is usually done in spring or fall.