Certainly, and the Parliamentary Budget Office has done more estimates of this than I have. The same type of problem applied equally to income splitting or some of the earlier versions of income splitting, and I'm glad to see that the government has revised it such that the fiscal impact is purely on the federal government and not on the provincial governments. But it is one of the impacts of changing the definition of income, which is what would happen under TFSAs in contrast to RRSPs, where withdrawals from RRSPs count as income, or where savings are kept outside of tax sheltered accounts, and therefore folks pay taxes on capital gains or on interest and dividend income.
I think it's an important point that decisions at the federal level on what counts as income impact provincial finances. In some cases, those amounts can be quite substantial, as they will be over time with TFSAs.