A big thank you to the guys at the Surrey Branch of Rail Future for their support and assistance. WLR gave a presentation there yesterday.
Also presented at the same meeting was Crossrail South. This is a plan to extend the lines into Waterloo to connect up to the Charing Cross lines, enabling a whole host of new journey options to the East and the North. It is very similar in principle to the Windsor Link Railway because (a) it reduces the operational inefficiencies associated with terminal stations and (b) connects a small missing link in the network for disproportionate gain.
It was originally the intention of the builders of Waterloo that it would be a through station, as they recognised the importance of a link to the City. Unfortunately, they gave up on this and built the City Line underground instead. This now suffers from severe overcrowding, which is why it is worth revisiting the original proposals.
The line to Windsor from Slough was also never planned as a dead-end; there were originally plans to extend it to Ascot. So again, the WLR proposals are in some way correcting these historical anomalies.
Putting the two schemes together means that you would be able to get direct trains from Windsor to the rapidly growing East of London, as well as other destinations such as with Luton Airport, which is woefully difficult to get to from the Thames Valley. Also, if the Davies Commission were to recommend Boris Island, such a link would be vital to maintain the prosperity of the Thames Valley.