Roger Federer continues to prove that age is just a number. At 31, the "old guy" on tour is the reigning world No. 1, has won six titles in 2012, including Wimbledon, and captured an Olympic silver medal. With Rafael Nadal sitting this one out, Federer has a clear shot at his 18th major title and first US Open win since 2008.

Andy Murray fought valiantly to reach the Wimbledon final but just couldn't overtake Roger Federer, who earned his 17th Slam title and seventh at the All-England Club. But when Murray faced Federer one month later on the same court for Olympic gold, it was a different story. Perhaps truly representing his country and the removal of the traditional white attire spurred him on, but Murray easily defeated Federer, earning a gold medal and, more important, respect. Murray might be the most dangerous player in the US Open draw if his knees can hold up on the hard courts.

Much like Federer, Serena proves that at 30 she is nowhere near ready to retire. In fact, she has dominated this summer, winning Wimbledon and absolutely crushing Maria Sharapova for the Olympic gold medal. She is on a mission, which surely includes trying to avenge her loss last year to Sam Stosur in the US Open final.

In recent years, the volume of shrieks, yells, grunts and screams coming from players during matches has come under scrutiny by other players, fans and television audiences alike. Although there are measures that can be taken to prevent such players as Maria Sharapova and Victoria Azarenka from creating what's viewed as a distraction on court, the best course of action is to train the next generation to dial it down a bit.

Novak Djokovic was so 2011. This year it has been all about Rafa, Roger and Andy. Djokovic has won three titles this year, including the Australian Open, but he has lost to Roger Federer twice. Although still a frontrunner to defend his US Open title, he's nowhere near the force he was a year ago.

World No. 2 Agnieszka Radwanska (pictured, left) and Germany's Angelique Kerber (right) are next in line for a shot at a major. Radwanska came so close reaching the Wimbledon final but just couldn't match Serena Williams' power this summer. Kerber had a breakthrough year last year, reaching the US Open semifinals, and can do it again.

For four consecutive years, the men's singles final has been played on a Monday, resulting in frustrated ticket holders and lower TV ratings. Yet renovation plans for the US National Tennis Center — proposed earlier this summer by the USTA — did not include a roof on center court or any show courts. It was at last year's Open that Andy Roddick and other top players met with the tournament director about being forced to play in unsafe conditions. Without looking at a “Farmer's Almanac,” we think weather could also impact this year's tournament.

With Rafael Nadal out and Novak Djokovic taking a few beatings this year, could Jo-Wilfried Tsonga step into the spotlight with his first major win? The Frenchman has come close, reaching the Australian Open final in 2008 and the Wimbledon semifinals in 2010 and 2011. A quarterfinalist last year, the No. 5 seed could make a run at Flushing Meadows.

Did her doubles gold medal with sister Serena rejuvenate the veteran Venus Williams? Every time she plays we wonder if this is it, the end. We wondered it last year when news of her illness surfaced, and we wonder every time she loses. This summer, she seems to be regaining some form, reaching the round of 16 at the Olympics in the singles draw and reaching the semifinals in Cincinnati. But how far the two-time US Open champion will go at Flushing Meadows this year remains to be seen.

John Isner broke into the top 10 in March, reaching No. 9, before dipping to No. 11. Right now, he's the No. 10-ranked player in the world and is trying to defend the Winston-Salem Open title and carry enough momentum into New York next week. We're not saying Isner is a favorite to win, but we'd like to see him repeat as a quarterfinalist.

On the other end of the spectrum are Andy Roddick, Mardy Fish and James Blake. We are almost certain their best days are over, but will Roddick go out with guns blazing and win another US Open title?

Sloane Stephens seems to be picking up the ball and running with it for the next generation of American tennis players. She reached the third round at the US Open last year and has followed it up by reaching the fourth round at Roland Garros and the third round at Wimbledon. Stephens seems ready to take the next step. Will she see the quarterfinals in New York?

Three-time US Open champion Kim Clijsters will retire at the end of the year. The US Open will be her final appearance in a major. She won here in 2010, but after a year plagued with injuries, her swan song might not last too long.

The former world No. 1 Caroline Wozniacki has all but vanished from the favorite's list at majors this year. In 2010, Wozniacki led the WTA with six tournament titles and 62 match wins. In 2011, she followed it up with another six titles and 63 match wins. But this year? She hasn't won a title and has reached only one final — Copenhagen, where she lost to Angelique Kerber. Maybe Wozniacki is working on her golf game.

On the eve of the US Open, 70-year-old line judge Lois Goodman was arrested and charged with murdering her 80-year-old husband, Alan, with a coffee mug. This true story is playing out like something on the Lifetime Movie Network with the US Open as its backdrop.

Rafael Nadal gave all he had to grab his seventh title at Roland Garros, and his body hasn't allowed much else since. Bowing out in the second round at Wimbledon, he withdrew from the London Olympics and the US Open citing knee tendinitis, allowing countryman David Ferrer or France's Jo-Wilfried Tsonga a chance to fill his very big shoes.