Some time in JULY 2010

Mike,
Nice of them to let us all know. The only announcement was that a new style v5c was "going" to be introduced from August 2010. This only affected people who sent in a V5 for any reason. The rest of us were at risk from the "Fake" documents when buying a car since then.
They've obviously got such a big problem now (of their own making) that they have had no option but to re-issue everyone RED V5c's.
ALL registered vehicles are being issued with a new RED V5; but this is planned to take up to SEPTEMBER 2012 to complete.
DVLA are advising you to fill in your BLUE V5 and get a new RED one if your thinking of selling your car (if you haven't received the new RED one by the time you want to sell your car)
If you don't automatically get your new V5C by September you'll need to fill in the old BLUE one and send it in.
for further info:

or
http://www.direct.gov.uk/v5c