I think that is one of the wishes on the B4i 'wish list' but I have now come to think that there isn't that much of a benefit in going with Swift as Obj C is good enough and one can be quite productive in it in a reasonably short period of time.
As someone who started developing iOS apps in Objective-C & now using Swift (3.0) - in both cases "teaching myself" - I think Swift is much quicker & easier to develop in. Swift is definitely less complex syntactically than Obj-C & the way it handles things like initialization, strings & type casting is much easier to deal with.
I've written 4 iOS apps in Obj-C, 2 in Swift (2.0) & am currently developing my latest app in Swift 3.0. Except for updates to existing Obj-C apps, I won't be using Obj-C again.
Of course, if you're developing iOS apps with B4i, the above comments are probably not relevant - unless you want to write wrappers for unsupported iOS frameworks.
- Colin.