Well, there will be two transits system available at least. The Waterfront East LRT (
https://www.toronto.ca/services-pay...work-expansion/waterfront-east-lrt-extension/) which I see no reason why they won't extend it to at least the Cherry Bridge entrance, and also the Ontario Line Station at Corktown. Once they open the Red Brick Promenade from 3C site to Distillery District, I am guessing it would take around 15 mins to walk to the station, which isn't be too bad.
In the renderings you can see streetcar inside the island. I guess they can prolly extend the cherry street streetcar down to the Island, tho I am not sure how they would do that without it being a pain. Most likely they will link it to East Harbour Hub, which should be about 20 mins walk? That will be really convenient.
Pretty sure there will be buses. There are always buses in Toronto. Owning a car in Villers Island would prolly suck tho. In my personal experience living in several cities, anytime there are bridges, there are traffic jam.
Honestly, between Regent Park, 3C, and Quay Side, and also East Harbour Hub (and the potential Hearn District), it will be a catastrophic planning failure if the residents cannot at least find something to fill their day to day needs.