Sadly, if you work for anyone but the government, you probably aren't. Ever since 401(k)s and other defined contribution plans were introduced in the early 1980s, scads of employers have been nuking their traditional defined benefit plans.
It's not hard to see why. With a traditional pension (the most common kind of defined benefit plan), the company takes on 100% of the responsibility to fund it. The employer has to set aside money - at least in theory - to make sure it can cut you your pension check when you retire.
With a 401(k), the company puts most of the financial responsibility on you. You invest in the plan by having money taken out of your paycheck, and you have to figure out how to invest that money among the sometimes confusing array of funds offered in the plan. True, the company might throw in a matching contribution to your 401(k) - but that match amounts to a whole lot less than what your employer would be on the hook for if it were running an old-school pension.