Civilization V is a different beast to Civilization IV. There are lots of new things, and the things that were kept have been changed. To help keep your feet on the ground, here's our guide to the new stuff (and don't forget to read our review!)
Luke, did you do these videos? I noticed the landscape features drawing in after you moved your view to another location. Is this because of your computer (assuming the eye candy would load faster on a faster rig)? What are you running this on?