The penalty was struck down as unconstitutional by the supreme court, last I heard. You can pay it, but it's optional. EDIT: Can't find a source on that, so I probably just misunderstood something.
What I expect to hit the JWs hardest is, part time workers are being limited to 27 hours a week because any more and the company they work for has to pay for health insurance for them (that's what I was told by my boss, so may not be 100% accurate)