Not sure why I didn't pick up on this one before (and I don't think anyone else has mentioned it) but there's some quite radical changes this December which tick a couple of boxes regarding problems with the existing timetable. Most notably the 15:52 Paddington to Worcester is to become a
HST▸ again (only running as far as Moreton). There's also an additional 15:22 Paddington to Great Malvern service (Class 180) extending the current 15:22 Paddington to Oxford service, and the 16:22 Paddington to Oxford service will now form the 'Halts' train through to Great Malvern, again a Class 180.
I can see the 15:22/16:22 from Paddington becoming a bit of a squeeze at least as far as Slough, but having a full length 15:52 and the extra 15:22 should remove Cotswold Line crowding at a stroke and hopefully spread out the number of passengers, and the Chiltern service from Marylebone to Oxford Parkway, which will be up and running by then, will add further London to Oxford capacity.
Also, something we've mentioned many times on here in the past, and that is a later service at weekends, and I'm slightly surprised (but delighted) that the 23:18 Paddington to Oxford service will extend through to Moreton-In-Marsh (calling at the usual stops) on Friday evenings.
There are several other alterations including another HST replacing a Class 180 in the early afternoon from Paddington, and several return journeys altered as a result of the changes:
http://www.clpg.org.uk/content.php?pagename=News-PageGreat news for Cotswold Line passengers!