I guess it depends on the company. My wife's company's standard buyout is 2 weeks per year worked (she works in travel). 1 week of severance per year worked is not great. In the current economic environment I would think people would be very hesitant to take it. Lets say I have been there 10 years, means I only get 10 weeks severance. I still need to find a new job and there are tens of thousands of other laid off engineers competing for jobs and those jobs are very limited. Odds of finding a new one before severance runs out is low.

If you don't take it you run the very real risk of getting cut with nothing.

Unfortunate situation all around.