riven, re HRP:
"Changes from April 2010 for parents and carers
Home Responsibilities Protection has been replaced for people reaching State Pension age on or after 6 April 2010.
From 6 April 2010, parents and carers are able to build up qualifying years through new weekly credits for the basic State Pension and additional State Pension. If you are a parent or carer, you will get a credit for each week in which you:
* are getting Child Benefit for children aged under 12
* are an approved foster carer
* are caring for at least 20 hours a week for people who are getting Attendance Allowance, the middle-rate or highest-rate care component of Disability Living Allowance, or Constant Attendance Allowance, or the need for care has been certified
There will be no limit to the credits awarded to parents and carers after April 2010, as long as you meet the qualifying rules.
If you reach State Pension age on or after 6 April 2010, complete tax years of Home Responsibilities Protection you have already built up before 2010 have been converted into qualifying years up to a maximum of 22 years. These qualifying years will also count towards bereavement benefits."
(from directgov)
If I am reading this correctly, I think this is actually better for carers than HRP, as there was that max of 22 years before. Now if you are a carer for longer than that you will continue to get credits towards pension etc.
OTOH, what will happen with SAHPs who have under-12s but will no longer get CB needs to be explained 
(apols if this has already been pointed out)