Check the latest ESRB ratings and you'll find T for Teen ratings for the original Metal Slug and Samurai Shodown 2, both for the Wii, SS2 is also headed for Xbox Live Arcade in case people haven't heard yet.
That's good news. Sure I have so many copies of MS1 already, but I've still wanted it as a VC title. Hopefully they make the game look better than they did for the Anthology.