There are 2 reasons why the Trans Am will never be built again. Firstly, Pontiac is done. GM is currently winding down production of Pontiac and Saturn products as part of its restructuring. As a result, all Pontiac products will disappear from the US market with the potential for reintegration as future surviving brands. Secondly, the Trans Am was
licensed. That's right. GM did not own the rights to the Trans Am name. The SCCA received $5 per Trans Am built, and GM gladly paid as profits soared on this model. If GM were to revive this brand, a new contract would have to be forged, and no current company would receive $5 for using its name, especially on a potential classic. The SCCA would demand a high premium in order to revive the classic Trans Am badge, and GM simply doesn't have any need to sell an alternative to the greatest production success the brand—perhaps the international market—has seen in ages.
Basically, GM won't sell the Pontiac Trans Am because there isn't going to be a Pontiac brand anymore, and GM can't sell the Pontiac Trans Am because the rights to the Trans Am name belong to the SCCA.