Much of the difference is cultural. National systems are built at huge expense, with lots of rigor with years of planning. earth.google.com just really came to life last week. Within many of these agencies are innovative and very talented people. We have been working with many of them introducing open standards, open source geospatial software. There has been some success introducing many of the latest advances into demonstrations, prototypes, and laboratories.
I'll bet right now there are marines and soldiers in Iraq that are pulling down Quickbird imagery over the areas that they are going to have to drive through and doing it through google maps. National imagery is often classified and hard to get out to the field.
Years ago there the government dominated investment in these areas. With open source, open standards, and internet, technology driven corporations - more R&D is occurring out in the open. We would all like to see governments adopt many of these technologies and flow their "accurate and approved" data through it.