There's not much that's being planned just because we get the games ... perhaps the Scarborough-Malvern RT ... but it's on the books anyway, it just speeds it up (perhaps unfairly, as Don Mills is probably more worthy ... but unfunded).
The other projects (Spadina subway extension, Airport train, GO improvements, Sheppard East RT, Finch RT) are already planned for completion just before then ... this will merely help keep the pressure on everyone to keep to the straight and narrow, and get it done.
We've seen the same in London, where there has been pressure to get various projects done by 2012; and apart from the Olympic Javelin service, all are permanent ... perhaps in the end, the only left-over infrastructure will be a couple of platforms at Stratford.