According to the Associated Press, Lionel Richie, Carlos Santana, Cyndi Lauper, Queen Latifah, Black Eyed Peas, Keith Urban, Jason Mraz and David Cook are all scheduled to light up the “Idol” stage.

And Pollstar has recieved word from Steve Martin‘s camp that the comedian will perform a song from his debut musical CD, The Crow: New Songs for the Five-String Banjo.

Rolling Stone reports Carrie Underwood will show up to sing her version of Mötley Crüe’s “Home Sweet Home,” the tune being used as this year’s farewell song for contestants.

Plausible rumors about the finale include Urban/Kris Allen and Lauper/Alison Iraheta duets.

The wilder buzz on the Web includes one report by US Weekly that Kiss will appear as backup for Lambert and another by MJ’s Big Blog predicting that the mascaraed one will be joined by the prince of glam himself – David Bowie.

Regardless of who shows up Wednesday, the most important performances will take place tonight, when Allen and Lambert will have their three final chances to impress the judges and the rest of the country.

Meanwhile, Bodog.com‘s sports book manager Richard Gardner is placing Lambert’s odds to win at 1-to-2.5 and Allen’s at 2-to1.

Both singers are doing their best to keep a level head and are encouraging fans to do the same and make the contest about the music and not their disparate personalities.

“For me, I hope that having the Christian vote doesn’t help with anything,” Allen said. “I hope it has to do with your talent and the performance that you give and the package that you have. It’s not about religion and all that kind of stuff.”

Lambert agreed, adding that he believes the contest “has nothing to do with your religious background, what color you are, your gender. It doesn’t have anything to do with that. It’s about music. That’s really important to keep in mind.”

Tuesday, May 19
George Lopez, No Doubt – “The Ellen DeGeneres Show”
Steve Martin – “The Tavis Smiley Show”
Heather McDonald – “Chelsea Lately”
Jewel – “The Bonnie Hunt Show”
Kenny Chesney – “Late Show with David Letterman”
Blink 182 – “The Tonight Show with Jay Leno”
Iron & Wine – “Late Night with Jimmy Fallon”
Eminem – “Jimmy Kimmel Live!”
Kathy Griffin – “Late Late Show with Craig Ferguson”
Snoop Dogg, Keane – “Last Call with Carson Daly”

Wednesday, May 20
Ricky Gervais – “Live with Regis and Kelly”
David Cook – “The Ellen DeGeneres Show”
Common – “The Tavis Smiley Show”
Frank Nicotero – “Chelsea Lately”
The Amazing Kreskin – “The Hour with George Stroumboulopoulos”
Grizzly Bear – “Late Show with David Letterman”
Bill Maher, Mandy Moore – “The Tonight Show with Jay Leno”
Dierks Bentley – “Late Night with Jimmy Fallon”
No Doubt – “Jimmy Kimmel Live!”
Hensley – “Late Late Show with Craig Fergsuon”
The Airborne Toxic Event – “Last Call with Carson Daly”

Thursday, May 21
Kevin Nealon – “The Ellen DeGeneres Show”
Busta Rhymes, Chris Franjola, Whitney Cummings, Ben Gleib – “Chelsea Lately”
Lionel Richie – “The Tonight Show with Jay Leno”
Billy Boy On Poison – “Late Night with Jimmy Fallon”
Green Day – “The Colbert Report”
Common, Busta Rhymes – “Jimmy Kimmel Live!”
Manda Mosher – “Late Late Show with Craig Ferguson”
The Kills – “Last Call with Carson Daly”

Friday, May 22
Mel B, Jo Koy, Natasha Leggero – “Chelsea Lately” – rerun
John Pinette – The Hour with George Stroumboulopoulos”
Common – “The Bonnie Hunt Show”
Ricky Gervais, Green Day – “Late Show with David Letterman”
Tori Amos – “The Tonight Show with Jay Leno”
Chrisette Michele – “Late Night with Jimmy Fallon”
Eminem – “Jimmy Kimmel Live!”
The Decemberists – “Late Late Show with Craig Fergsuon”
Glasvegas – “Last Call with Carson Daly”

Saturday, May 23
Dixie Chicks – “Austin City Limits” – rerun
Zac Efron, Yeah Yeah Yeahs – “Saturday Night Live” – rerun