Earlier quoted context omitted.
(Disclaimer: I work on Sync at BitTorrent) Sorry if that language is confusing - we'll try to clean it up. If you build a SaaS product using Sync that's totally fine and you're welcome to sell your service. What we're trying to prevent is people who try to sell something that we are giving away for free. Happy to try to clarify if there are any other questions.
Since you are already answering questions: when can we expect BitTorrent Inc to publish the protocol or at least add the option to run and use your own tracker for syncing? SyncApp is wonderful but I don't feel comfortable with it being closed source and your infrastructure being used. Thus I use it only to transfer files between computers I wouldn't mind sharing with the world.
As for your question, yes, we're planning on releasing a version that will allow for you to use your own tracker - unfortunately we don’t have timing yet for that but it is in the works. We're working hard to make a great product and to support everyone as best we can.
Also, we do have a dedicated forum for the Sync API http://forum.bittorrent.com/forum/106-developers/ in case you have other questions/comments. Thanks!