Thanks Maniac. Someone got the point!
Anyway, I just wanted to say it before someone else does... I know that Wario actually comes from the Japanese for bad, "warui," and that is the true meaning, the flipped "M" only being incidental. It does not work for Waluigi, because his name does not start with an inverted "L" (although his hat does have one). Nonetheless, Waluigi is an anagram for the word "igiwalui," which can mean "bad person."
What's remarkable about Princess Biichi is that her name continues the trend on BOTH levels. The letter "p" does become "b" when flipped. Also, her name still means something. She's a tad *****y!
Moad, Mart, Woshi, Baisy are all nonsensical in that don't word on any level.... although, I heard that SMRPG's Boshi--the spike collared, sunglasses-wearing evil blue Yoshi--was named Washi in the original Japanese version.