Samurai is for sure, not only because of the hints and Yoshi-P talking about it, but because I recall a shot of one of the developers desktops with a folder clearly labeled Samurai. I'll take Red Mage or Blue Mage (as both were hinted at in the anniversary event), but not both. At least not both in 4.0 series. Which leaves the final spot for my personal preference: Dancer.