From Jayski.com:

MORE: Landon Cassill — most recently an ASA racer who surged from 30th to fourth in the October race at Iowa Speedway — will graduate high school in February and journey to Hendrick headquarters March 1, his father said. Roger Cassill said Landon has already tested cars for Hendrick, and his future role with the team will include more of that while he’s groomed as a developmental driver. Cassill said his son may test Gordon’s “Car of Tomorrow” next week. “Hendrick was really good about coming in and saying they think he’s got the talent and they are more interested in developing him rather than making a bunch of promises,” Cassill said. “If he’s not ready he’s not going to race. As soon as he’s ready, he’s going to race.”(Des Moines Register)(1-3-2007)
UPDATE: Cassill will take part in two tests - one this month - while continuing to build a base of knowledge and experience. Hendrick Motorsports spokesman Jesse Essex said Cassill is the only driver with the organization other than defending Cup champion Johnson, four-time series champ Gordon, Busch and Mears. Cassill's progress toward a possible behind-the-wheel NASCAR career will be measured in baby steps. "Right now we're solely focused on seat time," Essex said.(Des Moines Register)(1-5-2007)