If it takes the severity of this downturn to boost the diversity of career paths that MBAs pursue, I'm all for it.
Management consulting and investment banking firms - particularly at top programs -- dominate the recruiting circuit. They essentially exploit a relatively risk-averse culture of MBAs to scoop up as many of them (they are usually the first on campus and the first to dangle job offers), and only to churn and burn them later on.
Even in good times, the average tenure of a post-MBA associate at a consulting firm or bank is 18 months. In good times, these people leave because they don't want to put up with the lifestyle. In bad times, it's because they get fired or laid off.
I really do hope that more people would go into clean tech, corporate, startup, nonprofit, and so forth.