Ah yes, that topic that is dredged up again and again (frequently by me!).

We had some discussions on whether the fare caps would be the same price
as Travelcards, given that Oyster Prepay is not yet valid on most
National Rail services. The latest set of Mayor's Q&As (15 Dec) on the
GLA site has an answer to that very question.

http://mqt.london.gov.uk//public/question.do?id=9496

"Oyster Pre Pay daily caps will be set at Travelcard prices with one
exception. The cap for zone 1-6 travel after 9:30 am and all day on
weekends and holidays will be £5.70 - 30p less than the corresponding
Travelcard price. Although Oyster Pre Pay is not valid on National Rail,
except for inter-available routes, 74% of customers buying one-day
Travelcards from TfL use only TfL services. Adhering to Travelcard
prices is preferable to adding one more set of price points to an
already too complicated fare structure.I hope that Train operating
companies will adopt Oyster smart card ticketing as soon as possible."

--
Dave Arquati
Imperial College, SW7
www.alwaystouchout.com - Transport projects in London