Online in NSMB Wii is not needed, and wouldn't work anyway.

[hYpnochronic]

Even if it had online people would just say "where's wiispeak???" and if it had wiispeak they'd say "but we want a headset", and if it came with a headset they'd say "but friendcodes!", and if no friend codes they'd say "but it's not HD". You get my drift.