Frankly, my money for SRT is on them doing nothing. In 2014 when it hits the fan they'll fall back on the old fallback plan of bumming old cars off Vancouver, which has Mark I cars that are as new as 1996 in its fleet.
As a plus, Toronto will probably get a really good deal on the things as the largest component of Vancouvers' Mark I fleet will be retiring in the next few years and the 30-ish newer cars become kind of orphanish.
Pretty much, it defers things for a decade, for a tiny fraction of the cost of either a subway or an improved SRT/LRT line. In the longer term they'll also have enough vehicles to try and refurbish them and cobble things along for another 10 years.
Not that I really think it's the best idea, but it's such a TTC thing to do.