You are quite wrong. HS2 phase 1 saves around 30 minutes to classic WCML destinations and phase 2 saves a further 30 minutes. 1 hour off London - Glasgow/Edinburgh journey times is not insignificant.
How exactly does it propose to do this?
If we take, for example, the Phase 2 proposal for a line to Manchester, unless this line extends significantly north of Manchester hten you have to use conventional lines to crawl to the proper WCML, or you have to leave it significantly further south.
The trainsets would be limited to 110mph north of Manchester (as 200mph tilting trainsets don't seem to actually exist) and once you account for the fact that it will take 30+ minutes to get from Manchester to Preston or more (it takes 40 minutes now, if you delete the intermediate stops you will save ten at most with superior electric train accelerations).
So its now taken you 1hr50 or more to reach Preston... compared with 2hr08 or 2hr as it happens now.
Once you include the fact that the trainsets will indeed loose time north of Preston you end up back where you started.
Any savings effectively have to come from deleting stops north of Preston, which could happen anyway really.
If you go via Leeds you end up with the same problem, you have to get from Leeds to York in 30/40 minutes even to break even, and you won't be able to do it any faster than that without building the high speed line all the way to York.
Bypassing Manchester and Leeds might help you marginally but then you have to build yet more high speed track to get links to lines in the middle of nowhere and it doesn't really help that much in the Manchester case, and only marginally in the Leeds case.
Edinburgh is not a suburb of Glasgow. From 2016, the trains on the fastest of the 4 routes between the two cities will take 40 minutes. Let's call it an hour including connections: that erases much of the time saving. Any Scottish HS line will serve Glasgow and Edinburgh. Nonsense to suggest otherwise. Glasgow is the larger city, but Edinburgh is the second most touristed city in the UK.
I meant that the Glasgow HS station would grab the Edinburgh-Glasgow traffic since any reasonable HSL to Scotland would go
via Newcastle and Edinburgh to Glasgow, giving you a 19 minute journey time using Shinkansen style commuter trainsets, perhaps 23-24 if you include an intermediate stop at Falkirk.
That said, there is little case for a Scottish HS line. The Scottish section of the WCML carries 3 intercity trains per hour in each direction: 1 London-Glasgow, 1 Birmingham-Glasgow/Edinburgh, and 1 Manchester Airport-Glasgow/Edinburgh. The new Birmingham ICWC trains will have 6 carriages; the new Manchester Transpennine trains will have 4. The London trains are fairly well-used but don't start getting really busy until Preston. Hardly stretching the limits of a double-track railway. Network Rail says the Carstairs junction can be remodelled for higher speeds and the Edinburgh branch of the WCML can be upgraded to 125mph. The only other justification left is for modal shift from air to rail, but the air demand is not really great enough to fill several 400 metre trains per hour.
Any Scottish HSL simply won't go via the WCML route, it would have to go via Newcastle to gain additional traffic that simply isn't present in Cumbria or South West Scotland.
EDIT:
I know how HS2 Ltd have generated these frankly ridiculous time savings figures.
They use the "typical" travel time as the baseline and then they use the stopping patterns north of Leeds and Manchester of the fastest trains to generate the travel times for the HS2 services, this seems rather disengenuous to me.
They can't hope to run an hourly Flying Scotsman via HS2, is there not a giant bottleneck on the northern ECML anyway thanks to Pacers and 125mph trains on the same route?
As for doing this on the WCML they don't appear to have accoutned for the problems I noted in my main post with regards the loss of speed north of Manchester.