Justin Bieber is actually doing double duty Sunday night: he'll sing his song "Take You" solo, and then team up with Will.i.am for their collaboration, "#thatpower."  Pitbull is also doing double duty: he'll perform "Live It Up" with Jennifer Lopez, as well as "Feel This Moment" with Christina Aguilera and an unannounced "special guest."  We're betting that special guest will be A-ha, the Norwegian '80s pop group whose song "Take On Me" is sampled in "Feel This Moment."

Other collaborations include David Guetta, Ne-Yo & Akon, who'll perform the song "Play Hard," and Nicki Minaj and Lil Wayne, who'll perform "High School."

Solo performers on the show include Taylor and Bruno -- debuting his new single "Treasure" --  as well as Ed Sheeran, Selena Gomez, Chris Brown, Miguel, The Band Perry, Macklemore & Ryan Lewis, Icona Pop and even music legend Prince, who'll be receiving the Billboard Icon Award during the telecast. 

Of course, since they're both going to be there, there's no reason why Taylor and Ed couldn't also team up for their duet "Everything Has Changed."

Other stars who'll appear on the show include Madonna, who'll receive a special award for her top-grossing MDNA tour; and presenters Celine Dion, Shania Twain, Ke$ha, Carly Rae Jepsen, Miley Cyrus, PSY, Kid Rock, Cee Lo Green and Alanis Morissette.

As for the actual awards, Taylor, fun. and Maroon 5 are the leading nominees.  Because there are so many different Billboard charts, it's impossible to list who's nominated in every single category, but Taylor, fun. and Maroon 5 are finalists in 11 different ones.  Taylor and Maroon 5 also are both competing for the night's big honor: Top Artist of the Year.  The other nominees in that category are Rihanna, Justin Bieber and One Direction.

Speaking of Rihanna, she's nominated in 10 different categories, while Carly Rae Jepsen's represented in nine,  thanks to the success of "Call Me Maybe."  One Direction is represented in eight categories.

Here are the nominees in a few of the biggest Billboard Music Awards categories:

Top 100 Song
"Some Nights"
"Somebody That I Used to Know"
"Call Me Maybe"
"Payphone"
"One More Night"

Top Billboard 200 Album
21
Babel
Red
Up All Night
Take Me Home

Top Duo/Group
Coldplay
Maroon 5
fun.
One Direction
Mumford & Sons

Top New Artist
Gotye
Carly Rae Jepsen
The Lumineers
One Direction
PSY

Top Pop Artist
Maroon 5
Bruno Mars
Adele
Justin Bieber
One Direction

Copyright 2013 ABC News Radio

“I didn’t tell anyone I was going to do it so no one had a chance to [give me advice],” said Quinto in an interview with movie critic Peter Travers on ABC’s Popcorn. “I just did it. No one in my life knew.”

The star’s high-profile ‘coming out’ two years ago, which preceded others like NBA player Jason Collins, seems to have help undermine the prejudice that publicly gay actors won’t be accepted by audiences in straight film roles.

Quinto said he has experienced no adverse effects in his career in the aftermath of his announcement, and thinks people are more accepting of homosexuals and marriage equality than they were a few years ago.

“I felt supported at the time in a really profound way, by fans and people that just know me by my work,” he said. “I think I’m in a really good place.”

Unfortunately your browser does not support IFrames.

Copyright 2013 ABC News Radio