Their lack of transparency on this matter sucks, but at least they haven't committed to making it proprietary: http://lists.cs.uiuc.edu/pipermail/llvmdev/2014-June/073698....
I've heard from various people that any decision on open source wouldn't happen until after 1.0 since the language syntax decisions haven't been nailed down yet.
The idea that you spend a few years to create a new language and have not even had a discussion yet about whether or not it will be open source is simply not credible.
Unless Swift was rushed to release because companies like Apportable were making too much progress and they wanted to herd developers back into the pens with new proprietary languages and APIs e.g. Metal.
I wouldn't put that past Apple. Remember the more we antagonize them the more likely their legal team might go "not worth the effort just keep it in house".
It's an unnatural forced use of the term expressly for that purpose, expressly saying something is not exactly what it is, isn't in anyway accidental.