This week's Steam Midweek Madness sale is for Super Meat Boy. The game has been discounted by 80% off it's normal retail price, so you can grab it for $2.99. The amazing soundtrack is also on sale, and that's going for $1.19. You have until Friday at 10AM Pacific to nab both discounted items.
Oh, and Super Meat Boy just released on Linux. So there's that news too.