There's no new official plan.
The City is generally looking for affordable housing everywhere now through their "Action Plan", but it's not a blanket requirement in particular areas yet that I know of. The Province has just allowed cities to require affordable housing through inclusionary zoning, but Toronto has not acted on that, and there's no indication when they might.
I don't believe that you're correctly characterizing how Section 37 negotiations go. No developers ever negotiate for less density, as more density is the whole reason for the negotiations in the first place. It's the City though the Planning Department and the ward Councillor who negotiate Section 37 benefits for the added density that the developer wants, and the City decides where the funds be allocated. They can go to a number of improvements, based on what the City feels the area is most in need of. Sometimes it's park or community centre renewal, better sidewalks, repaved streets are possible… and affordable housing units are becoming an increasing component of the mix. Sometimes they are in the new development being negotiated, sometimes they are built offsite.
Finally, developers pay to opt out of green roof standards? As best as I can find, the only option they have is to go with a white reflective "cool roof", but nearly everyone is going green. @ilikemilk
, where do you believe the developers have opted out of this system by paying?