This page has a link to the current zone, and here's the extended one that is coming into place in Feb next year.
It includes a pretty wide area IMHO. I don't think this is very smart. And I don't think I'm feeling comensurate improvement in the bus or tube network, nor reduction in pricing - either (or both) of which would perhaps drive more people onto public transport.
Can you imagine being a small business towards the edges of this new extension zone ?
Residents get a 90% discount, so perversely it can actualy become more attractive to live INSIDE the zone IYSWIM.
I think this is slightly grim, although I am aware of the congestion and pollution issues London faces.