I am using GForce mode to manually fly along the path using the mouse as a joystick. It works fine - just takes a little practice to learn not to over correct. You just hit Ctrl+G , to go back to normal hit Ctrl+T. If you lose control hit the space bar.

Info here:

http://www.keyhole.com/GoogleEarthHelp/GoogleEarth.htm

Navigating with GE -> Using a mouse -> Use GForce

Have fun!