Multicore-programming?

[cnb]

If I buy a multicore computer and I have really intensive program. How
would that be distributed across the cores?

Will algorithms always have to be programmed and told specifically to
run on several cores so if not told it will only utilize one core?

So is the free lunch really over or is this just an overhyped
phenomena?

Is threading with Python hard? Can you start several processes with
Python or just threads?