Original: He was traded during the 2010 NHL Entry Draft to the Florida Panthers, but was claimed by the Islanders after Florida placed him on waivers with the intention of assigning him to their AHL affiliate.
Simplified: He was traded to the Florida Panthers, along with Steve Bernier and a first round draft pick in the 2010 NHL Entry Draft, on June 25, 2010 for Keith Ballard and Victor Oreskovich. When the Panthers tried to send Grabner to their AHL team, the Islanders claimed his rights.