Gordon Bethune has personally stated that Cleveland-London is at the bottom of the list for 767-200 service. They have a shortage of these aircraft temporarily, but in a few years or so they will not. For example, Buenos Aires, which is slated to be a 767-200, will most likely be upgraded to a 767-400 if the loads are good. This will free up TWO 762s. The only reason the route is being served by a 767-200 when it gets launched in Decmeber is because its the only type of aircraft available. Once more 767-400s come available, maybe other 767-200 markets will be upgraded to, like EWR-BRU, because Sabena has recently left the market. But for now, widebodies are at a shortage, with the only ones up for grabs 762s. Only two 764s are being delivered this year, but there's still 18 more in 2002 and after.
Also, there really is not a gigantic rush to put a 767-200 on the CLE-LGW route. It holds the same capacity as a 757, except with more BusinessFirst seats and less Economy seats. Although it would be very appreciated if Continental put a 767-200 on the route, people will just have to continue flying a narrowbody. And if they have that much of a problem, well they can connect through Newark or take United.