The Swift syntax is bloody awful. They could have at least kept semi-colons to make it more familiar to C/Obj-C programmers.
For anyone who isn't a registered Apple developer, XCode 6 and Yosemite are up on TPB.
To be fair you are still allowed to use semicolons as stamement terminators... My biggest gripes are;
The bizzare function definition syntax.
The odd variable/constant type placement (though, they didn't have much choice)
The method calling feels clunky (Obj-C looks weird but is actually rather elegant*)
Due to the unfamiliar nature of the syntax, as someone coming from C, class definitions appear almost random in swift.
My confident, and probably inaccurate, prediction for the future is that Swift will be picked up by beginners and a few hobbyists... But serious developers will stick to Obj-C/C++ since they know it and will almost certainly be working in other C derived languages on other platforms/projects... Swift will then be silently dropped and remembered as an interesting little experiment
* I think C++ gets it right as methods are sort of functions in a struct and Obj-C gets it right as methods are executed in response to a message. Both beautiful implementations of their object models!