Downloads for the Revolution will not be free. That's not to say that some might be, as a promotion (i.e., buy Metroid Revolution, download Metroid for free) but if you are just downloading the game as is, expect a small fee.
The games available will be all Nintendo first party games. They are talking with other publishers, though, so it will be up to those publishers whether or not they want to make free money off of their back library. I'm personally hoping for Battle of Olympus, Faxanadu, and Star Tropics.
