The Swansea 'ValleyLines' (or so I sometimes call them), do not currently have any passenger services. As things stand, they will NOT be getting even a diesel passenger service in the new franchise. For clarity, by Swansea 'ValleyLines' I mean the following routes:
- Swansea - Resolven - GlynNeath,
- Swansea - Crynant - Onllwyn
- Swansea - Llandarcy - Clydach - Pontardawe - Ystradgynlais
- Swansea - Gowerton - Gorseinon - Hendy Junc. - Glanaman - Gwaun-Cae-Gurwen
The last two have significant portions of track missing as well as having no passenger services; electrification is a long ways off I think (although, if the 'train testing facility' comes off it might make sense).
Swansea electrification is a victim of funding for rail infrustructure being 'non-devolved'. The Welsh Government are allowed to invest in rail infrustructure if they want, but there is no money for it in the block grant so technically investing in Welsh rail infrustructure is the UK government's responsiblity. That said, while I think cancellation of MML electrification is an unmittigated disaster, I think the (hopefully temporary) cancellation of electrification to Swansea may have a silver lining. If it had been wired, the masts may have stood in the way of increasing capacity between Cardiff and Bridgend, which is sorely needed including the ability for fast trains to overtake stopping passenger services.
Except Cardiff to the Severn Tunnel; that's the only Network Rail bit that will be getting wires in the currently-planned future.