Expert Macintosh users who see "MacWorld" in an article know you don't know what you're talking about, just as most technology-literate readers would laugh at "MicroSoft," "QualComm," or "LexMark." Referring to a famous technology event without the correct name or spelling is a quick way to throw away your credibility. Saying "That's how I always thought it was spelled, and besides, everyone knew what I meant" is saying "I didn't bother to get the facts about my subject before I wrote my article." Don't be that writer.