According to EBRI, employers reluctant to offer annuities within their plans have a number of concerns. Those who offer a corporate pension, companies who want someone to be responsible for fiduciary issues and employers who would rather that income be handled outside the plan aren't exactly champing at the bit to provide annuity choices.

Interest on the part of employees is divided, with 21 percent of plan participants saying they'll use plan savings to buy an annuity or a product that guarantees monthly income for life. A larger proportion—48 percent—are very or somewhat interested in annuities, while only 20 percent of retirees are, and 31 percent of DC plan participants haven't yet figured out whether they'll roll over 401(k) assets into an IRA, leave it in the plan or just cash out.

And that indecision could have a lot to do with workers' expectations about retirement income, which could turn out to be pretty unrealistic. While 68 percent of workers expect that work income during retirement will be either a major or a minor source of income, just 26 percent of retirees report that that's actually the case.

Sometimes that's due to older workers being more expensive than younger ones and thus less employable; sometimes it's because they need retraining; and sometimes they end up with physical limitations that curtail their productivity.