According to today's London Lite, Chiltern are to accept PAYG from June
at the rest of its Greater London stations (Northolt Park to Wembley
Stadium) .

They are also to retail cards outside London.

"We are also happy to announce that we are working very hard with
Transport for London on being the first train company to sell Oyster
Smartcards outside London. We will be launching this to our passengers
in 2007"

C2C are also reported to be enabling PAYG acceptance at Dagenham Dock
and Rainham.

According to the press release on the TfL website they are going to extend
PAYG to c2c stations in the western part of Thurrock by 2008 (Ockendon,
Purfleet, Chafford and Grays). I wonder if they will move them to zone 6 or
have special fares for PAYG to work.