The good news, for the few that do so, is that you'll earn more miles for flying in full fare economy or business class. For most Canadians (ie those that don't their employers buying full fare tix and/or those whole only travel a few times a year) this isn't good news. Ultimately this aligns the earning on United flights with the Aeroplan miles earned on Air Canada's Transborder flights.
Here is the Aeroplan mileage earning chart for flying on United:
As usual we'd love to hear what your thoughts are on these changes!