Wokka,
Full benefits accrued after '15 kicks in can become payable as late as aged 60. You can take them earlier, at 55, but there will be a reduction as you trade off taking more cash upfront for less ongoing income. If you don't serve to your ADP point you will have to wait until your normal pension age before you get anything. If you make the 20/40 point, you'll get immediate payments (tax free lump sum and taxable income).
The g'ment has already announced plans to bring forward the planned increase in Basic State Pension age to 67 (to begin in 2026 and finish in 2028) and it will introduce 5 yearly reviews to consider future changes in that age. The first (5-yearly) review will take place sometime in the next Parliament, which begins in 2015. Lets face it, it'll happen as soon as the new g'ment is elected (I can't see any g'ment waiting until 2019/2020).
Somehow I don't think they'll tell us they'll be putting it back to aged 65.