Despite featuring in the Twenty20 side that played against the West Indies earlier this year, Pattinson has missed out on a place in the early group as Australian selectors opted to hand the pace duties to Pat Cummins, Ben Hilfenhaus, Mitchell Starc and Clint McKay, who will all play in the upcoming series against Pakistan, along with Mitchell Johnson, Dirk Nannes, Ben Laughlin and Ryan Harris.
And, although a Twenty20 specialist to begin with, Lyon has lost his place in the squad to veteran Brad Hogg and newcomer Glenn Maxwell.
The International Cricket Council tournament begins in Sri Lanka on September 18, with the Australian men's team drawn against Ireland and the West Indies.
In the most recent ICC World Twenty20, the Baggy Green lost the final of the 2010 competition to England in Barbados.
Michael Hussey, Shane Watson and Johnson are among the veterans from the previous campaign named in the preliminary squad for 2012, while Starc, Cummins and skipper George Bailey head the list of candidates in contention to experience the competition for the first time.
"The ICC World Twenty20 will be a fiercely contested tournament," chairman of Selectors John Inverarity said.
"A great deal of flamboyant cricketing talent will be on display and some games will be turned on their heads by 10 minutes of brilliance. The squad announced today is full of talent, enterprise and all-round strength. Within the 30 players named is depth and cover for all departments within the team."
Australia squad: George Bailey, Travis Birt, Dan Christian, Pat Cummins, Xavier Doherty, James Faulkner, Aaron Finch, Ryan Harris, Ben Hilfenhaus, Brad Hogg, David Hussey, Michael Hussey, Mitchell Johnson, Ben Laughlin, Mitchell Marsh, Shaun Marsh, Glenn Maxwell, Andrew McDonald, Clint McKay, Dirk Nannes, Stephen O'Keefe, Tim Paine, Rob Quiney, Steven Smith, Mitchell Starc, Adam Voges, Matthew Wade, David Warner, Shane Watson, Cameron White.