I would ask that you do some research into how the phrase "Notwithstanding any other provision of law" has been interpreted in the past.
A good place to start might be - "Statutory Interpretation: General Principles and Recent Trends", a document prepared for congress by the CRS (Order Code 97-589). It contains some interesting information on how the courts have interpreted that phrase.
Thus, "notwithstanding" the clear wording of the law, I still think there is a good chance the IRS will use some or all of its existing tax and penalty collection powers to get Obamacare penalties incurred by tax-payers.