The answer isn’t as clearcut anymore. Even for the lower tax brackets (ignoring the effect of RRSP withdrawals on income-tested benefits), a RRSP comes out marginally ahead of a taxable account for the typical dividend paying stock. The notable exception is British Columbia, which provides a generous 14.36% tax credit on dividends. A BC resident in the lowest tax bracket holding a purely dividend paying stock in a taxable account would return $304 more than a RRSP account (about double that of Ontario). A stock returning a mixture of dividends and capital gains would return $32 more in a taxable account than a RRSP account. So, unless you are a BC resident in the lowest tax bracket, you might find that a RRSP is still the most efficient location for typical dividend-paying stocks.

(PS: Also check out the following articles which compared investments located within a RRSP with those in taxable accounts.
Is an RRSP contribution better than a non-registered investment or a mortgage payment? from Efficient Market Canada.
The Retirement Savings Debate from PH&N)