Nice to see that Chris (Lattner) got his way. I chatted with him last WWDC right after the main Swift technical session, and he expressed the desire to open source it, but had no idea if he could get it through the powers that be. Supporting the standard libraries on Linux is certainly a surprise, though.
Golang is a pragmatic crowd. Go into #go-nuts on freenode, you'll notice that discussion rarely deviates from solving problems. Many links to the go playground. Go, from the beginning, shaped their community in this way. Consciously? Who knows. But the community turned out the way it did and I believe that's a result of their start.
Haskell is a computer scientist crowd. People write in haskell because they enjoy the functional paradigm and haskell is a purely functional language. Discussion on freenode? Very dense. People are expected to grasp topics easily and the community initially gives everyone the benefit of the doubt that they are capable of understanding it until they ask for more help.
When I look at swift, the only thought I have is that it is the new iOS language. I don't believe they'll be able to deviate from that. I don't see myself making iOS apps, so I don't see myself every writing a single line of the language. When I first looked at swift, my impression was that it was a wierd and somewhat-functional language that had a few unique things. Maybe I would have taken an interest in it. But at this point, I don't want to have to wade through a bunch of iOS specific questions to get what I need. I don't want to have to deal with being a beta tester for their linux implementations. I don't want to use the language when I'm probably going to be using it in a vastly different way than the rest of the community is. My interests are going to be second class.
It's not necessarily set in stone, but I think it is. In a world where there's a new language every day, I just don't see why I'd go with swift.