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LeBron James, the NBA's reigning MVP, ended months of speculation and suspense by telling the world Thursday he will play for the Miami Heat next season, leaving the Cleveland Cavaliers after an unsuccessful seven-year quest for the championship he covets.

James wasted no time in making a prediction during his exclusive announcement on ESPN: "We're going to be a real good team."

It's a huge victory for the Heat, which got commitments from superstars Dwyane Wade and Chris Bosh on Wednesday.

That duo, along with James, formed the upper echelon of the most-celebrated free-agent period in league history. And Heat president Pat Riley landed them all, a three-pack of stars to help shape his quest for a dynasty in Miami.

"This process has been everything I expected and more," James told ESPN about being a free agent. "I want to thank all six teams I got to sit down with."

He said he decided Thursday morning about where he would play.

"It was day-to-day," he said. "This morning, woke up and had a great conversation with my mom, and I was set."

He said the top factor in his decision was being able to help his team win. But he also this is an emotional time for him.

"I never wanted to leave Cleveland, and my heart will always be in that area," he said. "But I also feel this is the greatest challenge for me to move on."

His new home -- part-time or otherwise -- wasted no time beginning the celebration. Horns honked outside the arena -- and on Miami Beach, where Wade was watching the announcement with members of his inner circle.

"It's going to be crazy," Wade said.

James, Bosh and Wade entered the pros in the same year, the respective Nos. 1, 4 and 5 picks in the 2003 draft. They went their separate ways: James to Cleveland, Bosh to Toronto and Wade to Miami, where he won a championship, partnered with center Shaquille O'Neal in 2006. That year, James, Bosh and Wade all signed matching contracts, ensuring they were all unrestricted free agents at the same time.

Season-ticket sales for the Heat's coming 41-game season were suspended Thursday afternoon after the entire supply of available seats were sold out. Not every seat has been released for sale yet and some will be held back for single-game purchases at the 19,600-capacity arena.

FoxNews.com's Michelle Maskaly and The Associated Press contributed to this report.