For the amount of service that GO transit will run on those tracks its a great deal. It takes CN completely out of the picture. While CN will retain 'running right' on the corridor for those 3 trains, it will be under GO's jurisdiction meaning they'll only be permitted to do so
only when GO allows it and that will be at night and not during the day time when they would presented a potential source of regular delays to all-day trains running on the corridor.
Aside from that GO transit is going to invest a huge amount of money into this corridor, it only makes complete sense for them to own that investment.
All the track upgrades on the Lakeshore corridor have been paid for by GO transit, and yet the ownership of the corridor still belongs to CN. Who was quite content to do nothing to improve the line and spent only the minimal amount of funds necessary to maintain it. Yet they stand to benefit from these track upgrades that they didn't pay for as well and at the same time they retain full control. They scored a quite the coup on that one if you ask me. It would make absolutely no sense for GO transit to repeat that on an even greater scale on the Weston sub.
Also this sets a precedent and a bargaining point for future corridor purchases.
160 million for 17 miles
Next up should be the Kingston sub (Lakeshore East) from Union to Durham Jct. where the Kinston sub connects with the GO sub.
19 miles
And then the Oakville sub (Lakeshore West) from Union to Burlington West where it connects with the Halton sub just east of Burlington station.
32.2 miles
A little over 51 miles of track in total - 3 times that of the Weston sub. Though no doubt the price for this will exceed 3 times that of the Weston sub simply because CN uses this corridor more frequently than the Weston sub and there are many more tracks already in place. However it is not their 'main line' (That being the Halton & York subs) so it should be more than possible, with CN retaining running rights of course, and that should be only at night.
This is the rail corridor in the GTA now (old map doesn't show the recent extension to Barrie);
and this is how it should be sometime in the future;
With GO in green & CN/CP shared track in blue, perhaps after a merger... There was a lot of talk about that in the past, I'm sure if the current economic situation continues to deteriorate there will be talk about it in the future. In the GTA alone, layoffs have reached 15-20% of all running trade employees in both companies. Because of the downturn, freight volumes have dramatically decreased and it may not be economically for the freight companies to retain ownership of tracks that are expensive to maintain and yet are not vital for the company to function (i.e. the aforementioned portions of the Oakville & Kingston sub's). If theres one positive to this economic downturn for the GTA its the potential for the creation of a true regional transit system, one that would be the envy of North America and something that would give us an economic advantage. As someone who runs GO trains for a living, I can't wait to see all these future developments unfold.