The IRS is still finalizing some of their forms and because states depend on the information in the federal return, they often have a delay in some forms at the beginning of the tax season. After they finalize, of course, TurboTax needs to integrate the changes.
Here is a link where you can see estimates for dates particular federal forms will be ready.
IRS Forms Available Estimates
For state forms, select the type of TurboTax you are using and your state, to see when forms are expected. The dates may still change and this link will be updated.
State Tax Forms Availability Dates