Taylor Swift has made no secret of the fact that she will mention past relationships, good or bad, in her songs. With hits such as 'Should've Said No,' 'Picture to Burn' and 'Back to December,' which spotlights Taylor's own transgressions, it seems no one is off-limits, possibly including other celebrities.

Taylor's upcoming CD 'Speak Now' includes the song 'Dear John,' which is being speculated by many sources to be about rocker John Mayer, who Taylor was seen in public with several times in late 2009 and early 2010. While she never publicly commented on the nature of the relationship, the lyrics suggest the two may have been more than friends.

"Dear John / I see it all now that you're gone / Don't you think I was too young / To be messed with / The girl in the dress / Cried the whole way home / I should've known."

Lines such as "It was wrong / Don't you think nineteen's too young / To be played / By your dark, twisted games / When I loved you so," are adding to the speculation that the song is about Mayer, who is 12 years older than Taylor.

Mayer's dating history, with scorned exes including Jennifer Aniston, Jessica Simpson and Minka Kelly, seems to parallel the song's John, as well. "You'll add my name to your long list of traitors who don't understand / And I'll look back in regret I I ignored what they said / Run as fast as you can."

Still, it must be noted that John was the No. 6 most popular baby name in the U.S. in the 1970s and No. 9 most popular in the '80s. Plus, Taylor and John Mayer recorded a duet together for his latest album, so at least some of their time spent together was platonic. So don't hold your breath, because Taylor -- fiercely private about her love life, except in song -- will likely never reveal her John's last name.

Taylor has a busy few weeks coming up. Releasing her album, 'Speak Now,' on the steps of the United Nations October 25, she will make appearances on several TV shows, including 'Dancing With the Stars.'

Nominated this year for CMA Female Vocalist of the Year, the reigning CMA Entertainer of the Year has recently been added to the list of performers for the awards ceremony. She will join Brad Paisley, Carrie Underwood, Keith Urban, Rascal Flatts and George Strait in taking the stage November 10 at Nashville's Bridgestone Arena.