If George Osborne does a bit of scratching his head over summer and decides to go for Plan A+, which involves another £5 billion on transport infrastructure projects, I'm guessing that electrification from Bedford to Nottingham and Long Eaton to Sheffield will almost certainly be announced in this years spending review.
I think in order to obtain the benefits the Government would be looking for in such a 'Plan A+' things would have to happen faster than that. It will all be about bringing work forward, things which are already planned, and so can be sped up. There will then be a task in increasing the planning capability so that construction does not outpace design.
The kind of schemes you mention I think will form that new planning element, but the 'shovels in the ground' work will be on schemes we already know about, just happening faster. Things Network Rail have already pretty much done the detailed planning for.