You'll probably never see this combination (B/W Megaman + Arcade Classics Mario) again, so take a good long look at it while it lasts.
Oh yes, I've crossed over MM with Mario, too. Like Hyrule, the Mushroom Kingdom's a small continent mostly ignored by the rest of the world. Mario's an Italian-Mushroomian (this heritage got him mercilessly bullied in college), which is somewhat unusual but not considered a travesty like having Hylian and American parents (Hyrule had atrocious relations with America for a long time after WWII). But that's a story for another deviation.