I am self-employed and have individual health insurance, but I don't pay anywhere near as much as the minimum-quality plans that will be available under the current reform bills, since I'm comfortable with high deductibles and low premiums ("catastrophic insurance", as it's known). I don't claim to understand every aspect of the health care debate, however, I do know that if I have to pay $5000 more in health care premiums a year, then:
(1) I will sure as hell go to the doctor more often and for every little thing --- and I think the end result of that, if others do it, too, is queuing (like they have in those European nationalized health care systems) since everyone is going to want to get something for all the extra money they're throwing away. More demand paired with equal supply normally means higher prices -- but in this system it will mean (dreaded) rationing.
and (2) I'll try to keep my income under the threshold required to get subsides from Uncle Sam (Since I can make less if I want, I'll see no benefit in working more so that I can send the difference to the feds or my insurer.) My guess is that many people who buy their own insurance (self-employed, temporary workers, or employees that have discretion over how often they work or how much they make) will be in a similar boat. If you're close to the threshold ($43K), why bother putting in the extra labor just to spend it on health insurance you didn't want in the first place? The result of this might be lower tax revenues (inasmuch as laffer-curve type effects occur), lower productivity, increased "underemployment", and most importantly, the necessity of the disbursement of more subsides than expected.
These seem like poor incentives to me. I don't see why they don't just (1) create a government sponsored entity (like Fannie or Freddie), give it one-time funding, have its charter be to create insurance for all comers as a non-profit; (2) make it illegal for insurers to refuse coverage due to pre-existing conditions, and (3) expand disability coverage to all people whose insurance premiums exceed a certain level. Using this system, people who couldn't get covered before get covered, insurance companies will still be able to price the risk of covering such people (and such pricing would be kept honest by the non-profit's pricing, which should control for profit-motive), and no one would have to be forced to purchase anything.