The similarities between Super Mario World and New Super Mario Bros. Wii

I had no idea that New Super Mario Bros. Wii would spawn so much conversation! I figured the game would get a lot of attention, but I didn’t know it would bring about deep discussions about the Mario franchise. Some people seem to be very excited for this DS sequel, while others seem to think that it’s going to hurt the Mario lineage. That’s one thought process that I don’t understand, but I’m willing to listen!