Here is a great article and a summary of the new versus old CPP rules:

Current Rule – To apply for CPP retirement benefits you MUST stop working for a period of 2 months or your income must be below $934/month for those 2 months. That is the “Work Cessation Test”.

New Rule – The “Work Cessation Test” is removed as of 2012.  You can apply for CPP without stopping work.

Current Rule – Once you start collecting CPP retirement benefits you do NOT make any further CPP Premium contributions.

New Rule – As of 2011 a person receiving CPP monthly retirement benefits who continues working will be required to pay CPP Premiums (and the employer too).  These additional premiums will increase the person’s CPP retirement benefit beginning the following calendar year.

Current Rule – A person taking early CPP benefits will have the monthly benefit reduced by 0.5% for every month that the benefit is taken prior to 65.  So a person collecting CPP at age 60 will have their maximum benefir reduced by 30% (60 months x 0.05%) Persons who delay collecting their benefit beyond age 65 will have the monthly benefit increased 0.5% for every month that the benefit is taken beyond age 65. 

New Rule – A person taking early CPP benefits will have the monthly benefit reduced by 0.6% for every month that the benefit is taken prior to 65.  So a person collecting CPP at age 60 will have their maximum benefir reduced by 36% (60 months x 0.05%) Persons who delay collecting their benefit beyond age 65 will have the monthly benefit increased 0.6% for every month that the benefit is taken beyond age 65.  This will be phased in gradually between 2012 to 2016.

CPP_New__Old_Rules_2011_2012.PDF