Someone posted a while back about this icon. I thought they said they were not sure what caused it. I got one of these and saw what it was.
This is what happens when you have an app that is built only for Intel, and you are looking at it on a PPC system. It is not going to run. If it is built "fat", then it has both an Intel executable and a PPC executable hidden inside its bundle directory and it will run on either.
This particular app was the Mac OS X 10.4.x app put up by Chris Double for his SVG Video Demo.