XG15 is under way in Los Angeles.

ESPN previews four different events…

Skateboarding: “A confluence of factors makes this year’s Street competition one of the most fascinating to date. To begin with, there’s Ryan Sheckler. Arguably the most recognizable skater on earth, Sheckler comes to Los Angeles hot off a Dew Tour win, and the prototype for competition dominance. But a sagging economy has lured hardcore street skaters who normally focus on producing film segments to take a shot on the sport’s biggest stage. Can guys like Mike Mo Capaldi, Darrell Stanton and Nick Dompierre establish a new competition benchmark? And can any of them stop 15-year-old Chaz Ortiz from making the whole field look old?”

Moto X: “In an event known for big names, perhaps none is bigger than James Stewart. The 23-year-old motocross superstar is on pace to shatter the all-time record for Supercross wins, but first he’s making his first pit stop at X Games. James is known internationally not just for his dominance, but also his breaking down of racial barriers as the sport’s first African-American champion. The X Games gives Stewart the opportunity to test his newfound acceptance of his own fame with a whole new fan base.”

BMX: “Now that Dave Mirra has joined the Action Sports Retirement Tour (otherwise known as the Rally America Championship), it would seem he’s ready finally to cede the X Games BMX stage to other riders, except he’s still competing in both Park and Big Air and remains a gold-medal threat in both. He’s already the most decorated BMX rider in X Games history; will he pad his lead at XG15?”

Rally: “Travis Pastrana has won two of the three X Games Rally events, and his healthy lead in the 2009 Rally America Championship indicates he’s driving as well as ever. The flip side of Pastrana’s consistency is Ken Block, who’s considered the fastest driver in North America, but with a reputation for recklessness that has cost him wins in the past. In six Rally America championships this year, Block has won twice, finished second once and failed to finish three times. Whether or not he can finally break through for X Games gold after winning two bronzes and a silver in the past three might be the most fascinating question at XG15.”

ESPN also has coverage of the ever-elusive front flip, marketing guru Ken Block, 15-year-old skateboarder Chaz Ortiz, supercross star James Stewart and BMXer Van Homan.

You can watch a well-made trailer right here as well.

The Los Angeles Times has also run a series of stories detailing the this year’s events.

On risk, injury, and death…

On James Stewart’s debut…

On women’s skateboarding…

On Jake Brown’s aerial displays…

Lastly, I think James Stewart sums up the excitement of the events perfectly in this quote:

“The average person always thinks soccer, football and basketball players are the toughest athletes. But man, I think the guys that come to the X Games are probably some of the most gnarly and talented athletes in the world.”

You can catch the games all week on ESPN and ESPN2.