Swift doesn't have to become anything more than a language that works.
There's two issues here:
1. Swift working to develop apps for iOS
2. Swift being adopted by the software dev world. This has a direct impact on jobs, books, 3rd party support, etc...
Indie developers have a bonus if they play their cards right. They can put out an app and hope for the best and if it fails, they could have high demand skills for a great job.
If they select Swift and if it never gets adopted by the industry, those skills are going to be less marketable.
It'll probably take a while before we know how the industry adopts Swift, or even if they do.
If someone cares about jobs, they could monitor the job boards and see how ofter Swift comes up.
One upside to Swift is that you'd be spending less time learning syntax and more time learning APIs and Xcode and other things.
Again, you really think Apple won't make the industry adopt Swift?
I don't think they'd waste a bunch of time doing something like Swift and then let the industry tell them no. I've done both Objective-C and Swift. After some gripes I'd rather write Swift.