I hope they suprise us during WWDC.
Most of the time im writing simple and small programms (on a windows machine) that manipulate data, interact with the web, or work with files.
I really liked Swift from the start. It has all the language features that I like. Sadly, with no Windows support, and Linux being only a second class citizen, I'm not motivated enough to spend a huge amount of time with Swift.
I also hope that they provide a documentation like Go. The Swift book is fine but the examples of the Go documentation in addition to the text, the easy navigation between packages/structs, and the aility to jump to the implementation helps a lot while learning the language.
Also, defining portability as "porting to UNIX-like OSes that LLVM supports", I don't think portability is a big problem to solve given the current state of Swift (no multi-threading support in the language).
For example, Swift was just added to the FreeBSD ports collection (http://www.freshports.org/lang/swift)
(BTW, shameless plug, I send a weekly Swift newsletter here: http://SwiftNews.co)