That is always a risk with any type of investment or income.   We have also seen tweaks over the years that have actually improved the dividend tax credit and capital gains.  As well as changes to tax deferred and exempt investing (i.e. RRSP rules, TFSA, and lifetime capital gains rules).

You can't let the tax tail (or possible changes) wag the investment.  Make investments based on the merits of the company (or asset) and how they fit into your objectives.  And then structure them in a tax efficient manner based upon the current rules and/or reasonable expectations of future taxation.