Its really rather good. There are loads of nice new things you do in google earth.
I was chatting to somebody about taking a load of photos of different parts of munich, and mapping them into tgoogle earth- think of a number of markers around the fountain at Marienplatz, with photos taken facing different directions. Well, somebody else has thought of something waaay better
Digital Urban have a video on this page showcasing their way to display panoramic photo in a spherical object overlaid on goole earth. Its extremely impressive.
The coolest looking feature of Google sketchup to me looks is Photo Match. You bascially get a photo of a building, and fiddle about drawing lines on it so that sketchup can work out the panels and perspective points and stuff, and create the object in 3d, complete with your original photo elements "projected" onto walls of your sketchup object.
This video shows just that, getting a photo mapped into sketchup. Pretty awesome.