In the last couple of days, both Bing and Yahoo announced their top search terms for 2010.  Here they are:

For Yahoo:

1. Michael Jackson
2. Twilight
3. WWE
4. Megan Fox
5. Britney Spears
6. Naruto
7. American Idol
8. Kim Kardashian
9. NASCAR
10. Runescape

And, Bing:

1. Michael Jackson
2. Twitter
3. Swine Flu
4. Stock Market
5. Farrah Fawcett
6. Patrick Swayze
7. Cash for Clunkers
8. Jon and Kate Gosselin
9. Billy Mays
10. Jaycee Dugard

While it's not really surprising that MJ topped both lists, I am blown away by how dissimilar the two lists are.  Jackson is the ONLY common searched topic on the two search engines.  Venture Beat has an explanation:

Perhaps that’s not surprising — Bing is a much newer service, and
probably appealed to a more tech-aware audience. Yahoo, on the other
hand, reaches more users
(though it plans to replace its underlying search technology with
Bing), and its list skews even more heavily towards celebrities and pop
culture.

But I don't buy it.  Bing and Yahoo are both very mainstream search engines.  I could expect a difference of this magnitude on Powerset, Hakia or Wolfram Alpha, but the difference leads me to suspect that maybe there is a difference in methodologies.

I am looking forward to Google's Yearend Zeitgeist to see how that compares.