Wolverhampton to Walsall.
Pleeaase!
Getting to Walsall from the North is such a pain.
Many of the suggestions on here seem either typically contrary (why would you want to miss out the busiest intermediate station on a route - e.g. XC omitting Birmingham?) or Zero Sum Games (i.e. Charing Cross must be at 100% capacity, so any "Southern" service there would come at the expense of a "South Eastern" service), but Wolverhampton to Walsall ought to be a busy service if frequent enough.
The problem it'll have will be that you'd need to go to at least three or four services per hour to make it worthwhile, given the short distance and bus frequency.
I wonder if the Chase electrification will mean any longer distance services from Walsall to the "north" (i.e. New Street - Walsall - Rugely - Stafford...)?
Tradition requires that I suggest a Liverpool - Marches - Bristol service on these kind of threads (158s running via Shrewsbury/ Hereford/ Abergavenny, giving both Liverpool and Bristol links to the kind of places that they used to have before the "Everything must go to Cardiff" days. There's hopefully enough capacity on the Marches line (3tp2h in passenger terms) to allow this service in addition to existing services.
Plenty of other possible suggestions for services, but these would have to come at the expense of something else.
It'd help some longer distance connections if the SN service from Milton Keynes ran beyond Croydon to Gatwick or even Brighton, but what service do you remove from the BML to make way for it?
You could give Liverpool (or the WCML through Preston/ Carlisle) through services beyond Birmingham to the Thames Valley/ Bristol etc like they used to have in BR days (and the early days of VTXC) but would you remove the direct services from Manchester or Yorkshire to the Thames Valley/ Bristol to accommodate them? Give Ipswich back some through services to Nottingham/ Manchester, but that'd mean fewer Norwich services to those exotic destinations.
You'll find that even if your proposal benefits a hundred people and only inconveniences fifty, those fifty will be regular passengers who can be easily organised to complain (compared to a hundred people who aren't so likely to complain to their MPs about something not yet happening).
There's also the stock/pathing problems. Through services from Liverpool Street to Lowestoft/ Great Yarmouth would be useful for some, but three coach 170s are a waste of time west of Ipswich. North Wales to Birmingham via Crewe/ Stafford would be much faster than via Wrexham/ Shrewsbury, but do you have spare WCML paths for 75mph or 90mph stock (since Wales & Borders couldn't guarantee 100mph trains every time on such services)?
