More streets have been made "pedonale" or pedestrian only (which doesn't mean a taxi may not run you over - keep your eyes and ears open!) and many street directions have changed (also very dangerous in the short term as people forget which way to look when crossing, etc.).
From what I could tell at first glance it is now nearly impossible to drive across the center even if you have a ZTL for your car. Below is a picture of one of the new changes, a circle in Piazza Goldoni, and now the Ponte Alla Carraia is two way vehicular traffic, with what seems to be a one-way bike lane... strange.
Here is a page with all the information, but in Italian only. Of course this being Florence a lot websites that should have this info don't or don't even exist anymore which is just amazing...
Here is a new map of all the changes:
And here is a PDF of the same map.