The $7,500 is a tax credit (and not a deduction) and will reduce your federal tax liability by that amount. You don't have to itemize to get it as it's a below-the-line tax credit.
I just did my taxes and I'd be lying if I claimed that the $7,500 tax credit didn't help. As did the "instant" $2,500 rebate from Calif. soon after I got the car early last year.
It's only a matter of time though before this tax credit is done with once Tesla produces 200,000 vehicles; that day is not far away - probably 4 years from now after a few months of production of Model E. Tesla may have to re-price their offerings a bit at that time, probably at the expense of their profit margins, to offset the loss of the tax credit.