You are misunderstanding - this isn't about which is better. Almost all new application code will be written in Swif, but swift doesn't bridge between C and the Swift/obj-c runtime, so Objective-C will continue to be required for writing the glue layer.
Additionally, this is just version 1.0. So nothing rules out that if Apple sees the language being widely adopted, other improvements in the FFI area aren't made.
Yes, and I think people should head to Swift if it fits their needs. That is very different from Objective-C losing support however. Objective-C is not going away.
From my point of view, many will jump to Swift if given the chance.