Is TrendMicro Better than McAfee

Hotmail has chosen TrendMicro’s anti-virus service over McAfee, which it had been using. What does this mean? That TrendMicro is better than McAfee?
Cnet writes Martin Hoffman, chief executive of Ninemsn, which operates Hotmail in Australia and is half owned by Microsoft, said in a statement that Hotmail will be able to provide a “safer online experience” using Trend Micro’s products because they provide “deeper antivirus protection.”
PC World’s July 2003 “Pest Zappers” aritcle rates anti-virus products.
Is there indeed a big difference between one anti-virus product or another. If Microsoft uses one product as they feel it’s technically better (as opposed to a marketing or monetary decision) than another product should you also consider it for your business?