To add a little balance here:

the 6.4% will only affect people retiring after 2015, so granny who is already retired won't lose income.

I have mixed feelings on this. Although I believe a promise should be honoured, I think it is better for everyone to take a little bit of pain now and keep the system afloat, than for all to bury their heads in the sand, only for it to all blow up in our (read my) faces in 30 years time. At least now I know that I need to put a little extra more away, to get the same benefits. Clearly this issue is going to impact those who are going to retire in the next 10 years most, as they have less time to make alternative arrangements. My other concern is that they have done this twice now - if this is agreed to, how many more times will it happen before I retire?