I'm going to be in Ottawa, rather than Toronto... for school...
I'd go see Alexisonfire in September, but they're playing with the Used, which makes me really want to not... and tickets are like 40$...
However the Underground Operations Unity Tour should be under way by then... a bunch of underground super-indie punk bands in a small venue... nice...
Protest the Hero is playing a release show for their newest album on the 30th of September, which, though technically not fall, I consider to be noteworthy enough to include.
And if I'm in town, I'll go see Thrice, the Bled and Underoath (though I only like Thrice, to be fair). It's fun to skank around all the kids who think they're cool by flailing the air

...
And I guess that's all... for now...