Technically, isn't this what the VSL Performance tool does? It's a piece of software designed to "synthesize" legato performance created from stringing hard coded samples together. I've been doing this in some form or another for 15 years, I don't care how user friendly or real the sounds, samplers or synthesizers get, you WILL have to take time to get the mix to sound perfect in your mind..... Unless someone creates a Holo-deck like on the enterprise....Thats different.
-Ben
-Ben