I'll be personally surprised if it even hits 2million without aggressive bundling with the Vita and PS3. It will need heavy advertising and Crash Bandicoot for it to exceed 5 million. There's a huge backlash from fans of Smash Bros that believe other companies aren't allowed to make a game for a genre once Nintendo creates an IP for that genre, so the constant bad mouthing of the game on most on-line forums won't do the sales any good.
Before I get shat all over. The Outfoxies. You're welcome.