One way to look at your tax rate when you retire and use your 401(k) or other tax deferred savings/retirement plans, These plans are now seen as your employer - and you are the employee where you determind your annual salary, based on that income you will pay the going rate just like you are employed. On top of that is any additional income like Soc Sec and Dividends, part time work, what have you you will also pay income tax. So remember - your 401(k) is your employer when you retire, treat him right!
Roth plans are great too - if you qualify.