Wait a second. cars over 226 registered before 2006 are added to band K not F. Is there an official source saying this yet?
That's what I was thinking too.
http://www.direct.gov.uk/en/Motoring/OwningAVehicle/HowToTaxYourVehicle/DG_10012524
The site the OP posted says that
The cars that will experience the biggest jump in VED are those emitting over 226g CO2 per km, registered after 1st March 2001 but before 23rd March 2006. These cars, which move from the current band F to the new bands L or M, will see their VED jump from £210 to a minimum of £415 from next year - a significant amount relative to their likely value.
Thing is that these cars are NOT in band F at the moment anyway. They're £260 to tax now, not £210!!!!!
A quick search on an internet site shows that this story was from 2008 originally and is therefore complete borlocks
http://web.archive.org/web/20080408083737/http://www.wisebuyers.co.uk/motoring/on-the-inside/55/