Definitely. Banks want former bankers. Consultant firms want former consultants. If you don't already have one of those backgrounds you're going to struggle in the job search. Have a back-up plan if you can't actually end up switching careers--make sure the $$$ adds up: You're blowing 2 years of opportunity cost and going into 6 digit debt for 10 years. Do the math and make it make sense.

Also, regarding networking: 50-70% of your class-mates will not be career switchers: They'll already have banking or consulting backgrounds, already speak the language and know each other's firms. Make friends with them or you're not going to reap the much-touted "networking" benefits of MBA school.

I went to a top-10 school, but happened to graduate the year Lehman and Bear imploded, and ended up right back in engineering. So, for me it ended up not being worth it financially--but for folks who graduated a few years before me it was totally worth it. Do the math and make sure you can deal with that risk.