When I went from my Nexus One to my Galaxy Nexus, the phone downloaded all of the apps I had installed on the old phone automatically when I logged into Google. I didn't have any paid apps through Google, but did through the Amazon App store. As soon as I loaded the Amazon App store, it showed a list of all of my apps and let me download them individually. I had uninstalled many, so I appreciated being asked.
Very seamless in my opinion.