Notable changes:
- Weekend hourly Kitchener service to Mount Pleasant, including 30 and 33 buses
- No off peak/weekend service on Stouffville and Barrie (exception being some trips to Allandale on weeekends), buses will replace during off peak and weekends
- Milton buses will be rerouted to LW line, highlight on one of the branches being 7 day Milton-Oakville service (30 min on weekdays), and weekend service will finally include Lisgar
- 12B is back for the season, and more 12C trips between Fairview Mall in St Catherines and Burlington
- New 17 bus route connecting the likes of University of Waterloo, Wilfried Laurier University, University of Guelph, and McMaster University, via connections at Guelph Central, Aberfoyle Park and Ride, and Aldershot GO
- 19 will no longer service the downtown Mississauga and go straight to Square One from the transitway
- 21 is split into 21A Milton-Oakville. 21B Lisgar-Clarkson via Meadowvale/Streetsville, and 21C Erindale-Port Credit via Square One/Cooksville
- 25 will have its seasonal weekend service back to Toronto Premium Outlets on Saturdays
- 30 will have hourly weekend service between UW, WLU, Kitchener GO, and Bramalea
- 31 will no longer run in the day time on weekends due to new weekend train service and most trips are replaced by the 33, including the bi hourly Guelph service now heading to York Mills instead of Union
- 34 will be combined with the 94 stopping at Square One, Dixie/Renforth transitway, Pearson Airport, Yorkdale, Sheppard-Yonge, Scarborough Centre, and Pickering, further highlight including the route being an hourly 24/7 route
- 36 will no longer run on weekends between Downtown Brampton and Bramalea Bus Terminal (BCC), as replaced by weekend 33 service
- 40 is going to have 20 min peak service and some 20 min trips on weekends
- 41A is now extended to Pickering, providing more service between Square One, 407 Bus Terminal, and Consumers Business Park
- 45 will no longer run its 45B branch affecting riders between Unionville and Hwy 407 Station
- 47 is one of the bigger changes as this route will have most times at 30 min service at all 7 days a week, and its seasonal service is back now running to the new Major Mackenzie West terminal near Wonderland
- 52 (thankfully) has its hourly service back on weekends and both it and 56 will no longer run local service on Highway 7/Winchester Rd, therefore finally using the new 407 extension for the first time, still stopping at the Park and Rides along the way. 52 will also have its seasonal service back to Major Mac West/Wonderland
- 65 will run a lot more because of the off peak and weekend changes on the Barrie Line
- 66 will no longer run to Yorkdale, and will start/stop its trip at the 407 bus terminal.
- 68 is no longer going to Barrie Bus Terminal, just stopping and terminating at Allandale Waterfront
- 70 and 71 will run a lot more because off the off peak and weekend changes on the Stouffville Line
- 81 and 88A are now being discontinued
- 96 will have its seasonal service back to Toronto Zoo
Let me know if I missed some changes but this is all I have caught.