Duke coach Mike Krzyzewski, who saw James earlier this week at the LeBron James Skills Academy basketball camp, also commented.
"LeBron has a huge heart,'' Krzyzewski told ESPN.com's Andy Katz. "This decision is a great decision for him because he's following his heart and he loves his home."
Nike, James' biggest endorser, released a statement that said: "Like basketball fans around the globe, we are excited to support one of the world's greatest athletes as he enters the next chapter of his career. We look forward to seeing LeBron step back on the court in Cleveland."
In the days leading up to LeBron's decision, much was made of the infamous letter that Cavaliers owner Dan Gilbert had issued in the wake of James' departure in 2010, calling James a "coward" for leaving. James addressed the letter in his essay.
"I've met with Dan, face-to-face, man-to-man. We've talked it out," James said. "Everybody makes mistakes. I've made mistakes as well. Who am I to hold a grudge?"
Gilbert weighed in himself on Twitter minutes after James' announcement.
Welcome Home @kingjames. I am excited for the fans and people of Cleveland and Ohio. No fans and people deserve a winner more than them.....- Dan Gilbert (@cavsdan) July 11, 2014
"I'm thrilled with the news," new Cavaliers coach David Blatt told ESPN.com's Jeff Goodman. "It's exciting for the team, the state and for basketball. Life is full of surprises."
Reaction to James' decision was decidedly different in Miami than in Cleveland. Arison expressed disappointment on Twitter shortly after James' announcement.
I am shocked & disappointed in today's news. However I will never forget what Lebron brought us for 4 years. Thanks for memories @KingJames- Micky Arison (@MickyArison) July 11, 2014
Riley issued a statement Friday evening, saying: "While I am disappointed by LeBron's decision to leave Miami, no one can fault another person for wanting to return home. The last four years have been an incredible run for South Florida, HEAT fans, our organization and for all of the players who were a part of it. LeBron is a fantastic leader, athlete, teammate and person, and we are all sorry to see him go."
James, Bosh and Wade all exercised options in their contracts to become free agents this summer, but the thinking was that they would redo their deals to give the team financial flexibility in an effort to upgrade the roster.
Now, the future is uncertain in Miami. Sources confirmed to ESPN.com that Bosh is finalizing an agreement to return to the Heat on a five-year, $118 million deal after weighing a maximum-contract offer from the Houston Rockets. The team also is making a push to re-sign Wade. Aside from Bosh and Wade, the Heat currently have just four players who will be under guaranteed contract for next season.
James has spoken with former Heat teammate and free-agent forward Mike Miller about joining him in Cleveland, a source told ESPN.com's Brian Windhorst.