The public option is, in principle, remarkably like introducing public colleges. You offer a cheap substitute to private colleges, while offering decreased quality. You obviously still have private colleges, the Ivy Leagues case-in-point, and you still have public colleges. both work in harmony, and both fulfill the requirement in the public for education.
The health care bill will essentially be the public colleges. We will allow people to buy less comprehensive plans, with the option to differ to more comprehensive, but more expensive plans. Economically, this will defeat the monopoly that the health care companies have on their industry, and will encourage them to stop outrageous price hikes.
While I agree that, in the very long run, this is government take-over of healthcare, but this is only if it is given that the only changes in the healthcare debate for the next fifty years will be this health car bill. Whether conservatives allow the status quo to remain unchanged for such a long period, I seriously doubt.