Gov. Mitt Romney of Massachusetts has decided not to seek re-election in 2006, a source told The Associated Press on Wednesday, fueling speculation he will seek the 2008 Republican presidential nomination. [GOP candidates lining-up further justifying call by Walter Cronkite for a DNC 2006 mid-term conventionn to decide on a candidate to put full effort behind while GOP takes itself and its candidates apart in 2008 primaries]