The WAG are going to be in an awkward position if the next WCML franchise means wiring from Crewe to Chester.
It means London - Cardiff and London - Chester will both be electrified routes, which potentially downgrades Holyhead and Swansea to "second class" (fewer London services?).
But since those in Wales have been arguing for greater power over rail, the cost of wiring Chester - Holyhead and Cardiff - Swansea would come from the WAG budget.
All of a sudden having that control/power over rail is a double edged sword, because it'll be up to those in Cardiff Bay whether they want to spend the money on infrastructure (or they want to be the ones who turn this down). Can't blame London any more...
Interesting point, though I think Westminster are waiting for the Welsh Assembly to cough up some money towards Swansea and ValleyLines electrification despite the Welsh Assembly having turned down further powers for rail (meaning as far as I can tell any funding from WAG for rail has to be diverted from money allocated to WAG for other purposes). I'd be very supprised if service cuts to Swansea were on the cards, with or without wiring, because without wires DfT will order the bi-modes. Holyhead though would be difficult, without a fairly major shakeup of service patterns (the hourly ATW Holyhead services would have to cease extending towards Wrexham) the London trains would be the only services using the wires west of Llandudno Junction (and I don't know whether the Llandudno - Manchester route would be all wired) so it might be hard to make a case for wiring. That leaves two options, keep the awful Voyagers or do what they do once a week anyway and drag a pendo behind one of their 57s. I'd probably take the second option, but how much do you have to cut the frequency to get away without too many locos? How many 57s would be needed for a 2-hourly service (more trains per day, but without the hourly-ish peak trains which would add on loco requirements).
You'll not electrify all lines by 2050 though, there will always be bits not done yet. Much of XC is already electrified, but not all - I don't think it will ever be 100%.
It depends how fast wiring can be done, if we can only manage 60 miles a year then perhaps not, but with Network Rail suggesting at one point they could have 3 factory trains each capable of a mile a night (200 miles a year, but I'm not sure if you have to double the time they've given for double track lines) we shouldn't have a problem.
Anyway, I'm guessing at a halfway-ish figure, 100miles per year, and I reckon it should be possible to wire all INTERCITY routes (save 1 or 2 trains per day jobs like Pembroke Dock and Carmarthen, which dragging with a 75/90mph diesel locomotive would cover easily) by 2050. Given that the Voyagers, 222s and 180s should last a good while yet and IC125s can reach 2035 I think we can and should avoid ordering any new diesel stock capable of more than 100mph. Replacing elderly regional/surburban DMUs (Pacers being the biggest challange due to the 2020 regulations) without having to order new diesel trains sadly is likely to be unavoidable, but I doubt 125mph bi-mode INTERCITY trains with 26m carriges (which may prove to be almost as restrictive in terms of cascades for IEP as the 166/165's extra width) would be that useful in a casscade to replace, say, 153s.
id love one of them. 
