TurboTax certainly can change the calculations and modify the forms (just not as 'final' forms). Other software does that.
The IRS released the "draft" version in July, and the main purpose of the "draft" version is so software companies can start programming the cosmetic changes in the form. The actual calculations are not dependent on the cosmetics of the forms, and the calculation information is usually available long before the "draft" forms (in this case, the law was written in 2010).
