This Week, Roger Whitney introduces a new service YOU ASK I ANSWER, where you can ask your retirement planning questions and receive a response.
Then he begins to answer the question, will I have enough money to maintain my lifestyle during retirement?
The first step to answering this question is to determine what your retirement lifestyle will be. You do this by breaking your retirement lifestyle into three buckets:

Retirement Essentials. Those retirement expenses needed to maintain your household (housing, utilities, food, insurance, etc.)
Retirement Lifestyle. Those retirement expenses for things that enrich your life (travel, entertainment, home improvements, hobbies, etc.)
Retirement Dreams/Legacy. Those special things that you would like to accomplish (major travel, gifting, purchasing a second home, etc.)

Breaking your retirement lifestyle into these three buckets gives you the flexibility to adjust your retirement lifestyle each year based on how your retirement unfolds.
Once you do this, you need to consider how you will spend during retirement. For example inflation. Consider what your personal inflation rate is based on your spending habits.
Also consider closely whether you want to spend more earlier in retirement with the understanding that you will lower spending in later years. In essence, buy yourself more lifestyle now, while you are younger and healthier. 
Once you've completed this step you are well on your way to determining how much money you will need to maintain your lifestyle in retirement. 
In future podcasts, he'll address the next steps in this process.