This is great news and will help lead to wider adoption. I hope that some progress will be made for handling large files since currently it is stored in-memory: https://github.com/webtorrent/webtorrent/issues/86
I've personally been working around this using a custom fork that messes around with the simultaneous connections settings, and it seems to help quite a bit, but I still get freezing from time to time when I download a large number of torrents simultaneously.
I wonder if an alternative implementation in something like Rust on top of WASM might make those kinds of issues easier to avoid by making more efficient use of resources.