There are over 10,000 tax jurisdictions in the United States going all the way down to city level. It gets even more complicated with the taxes themselves as there can be exceptions carved out for particular goods based on ingredients and other crazy crap.

If the flood gates truly are being opened then expect so see an entirely new industry that crops up offering services to businesses that aid in collecting these taxes. This cost will passed down to customers in addition to the additional taxes.

Fun times...