Real time trains has some new services (some are extensions of services to/from south west Wales to Cardiff) running through to Bristol from December 2026 timetable

Example Fishguard to Bristol
https://www.realtimetrains.co.uk/service/gb-nr:L00529/2026-12-14/detailed

Looks like they will be worked by class 197 DMUs

In England looks like like stations served are Filton Abbey Wood, Stapleton Road and Bristol Temple Meads.   
Slightly intrigued by including Stapleton Road, but it is fairly east to park for free nearby so maybe it is for people travelling to Cardiff who object to paying for parking

I think this is first phase of proposed services calling at some new stations (usually referred to as Burns stations) along South Wales main line.

There is a rumour that rail growth in Wales will mean additional new trains will be ordered, so possibly bi-modes will get ordered for Burns station services

 
Interesting ... and that's the first full weekday of the Nationalised Great Western operation.   There is sense in calling at some of the lesser served stations such as Stapleton Road ...

Looking at other services for the new timetable I note: DMH MKM WVS

https://www.realtimetrains.co.uk/search/detailed/gb-nr:DMH/2026-12-14/0000-2359?stp=WVS&show=all&order=wtt - a failure to address the peak gap that was been created at Dilton Marsh last December

https://www.realtimetrains.co.uk/search/detailed/gb-nr:MKM/2026-12-14/0000-2359?stp=WVS&show=all&order=wtt - and no significant changes at Melksham (weekend services look unchanged too).

Bristol to Oxford remains every 2 hours

12 trains from Westbury (and mostly from beyond there) terminating at Salisbury, and 11 trains starting at Salisbury and running to / via Westbury
Early days, of course ...

 
Getting 'not found' pages for both those links

 
I can see John D's link, but as said, grahame's links not visible.

 

Sorry - my (coding) bad - it was expanding the MKM and DMH abbreviations within the URLs. Fixed.