If they are not using BitTorrent then Sync would provide a new, plausible way to stop ISPs from blocking that specific protocol.
Well, apparently Blizzard does. :) Quoting http://www.wowpedia.org/Blizzard_Downloader
There's also http://debtorrent.alioth.debian.org/
Apparently CCP is planning to use bittorrent for the next generation launcher for EVE online:
http://community.eveonline.com/news/dev-blogs/74573
Well, apparently Blizzard does. :) Quoting http://www.wowpedia.org/Blizzard_Downloader