Today is Valentine's Day but it is also the 2010 Winter Olympics. Google & Bing decided to stick with changing their Olympics logos, while Yahoo and Ask.com placed special Valentine's Day logos up today. I am constantly updating our Vancouver 2010 Olympic Logos, which is now up to thirteen logos from various search engines and forums - so make sure to check them out.
Update: Although Google shows an Olympics logo, as Michel points out in the comments below, if you hover your mouse over the logo an Alt tag (alternative text tag) pops up saying Valentine's Day. Plus, the scatting marks shows a heart in the logo - nice touch Google:
Search Engine Roundtable:
Forum discussion at Search Engine Roundtable Forums.