Earlier this month, news broke that the ESRB had given Super Mario Galaxy a rating for the Wii U (E for Everyone, of course). The official game pay is up on Nintendo's online store, and you can purchase the game starting tomorrow for $20.
"Become Mario as he traverses gravity-bending galaxies, traveling in and out of gravitational fields by blasting from planet to planet. Control Mario with the Wii Remote™ and Nunchuk™. Power-up to reach inaccessible areas. Collect Star Bits to either stun enemies or feed Lumas."
And hey, it'll be Christmas Eve, so you can definitely write this purchase off as a holiday gift to yourself.