Plate format from 2010
From 2010, the year identifying number will continue to use the last two digits of the year for cars registered in March, with 50 added to that number for those registered in September.
So, for example:
2010: March 10 and September 60
2011: 11 and 61
2012: 12 and 62
2013: 13 and 63
2014: 14 and 64 etc.
I reckon your question will be academic by then as the politcians will have taxed car users so heavily that nobody will be able to afford to drive anyway! They will be able to afford it of course - just claim it back on expenses.....