I keep seeing posts on Swift and I am trying to figure out what its purpose is. I know it is a new language but is it an Objective-C replacement or more of something that should/can be used alongside Objective-C? Another question, where does this leave beginners? Will job positions for junior iOS devs require Objective-C and Swift knowledge or could one get by with just Swift knowledge?
You'll need to know both, at least for the time being - many open source libraries are written in Objective-C, so if you need to make tweaks, you'll need to understand Objective-C. Also, a lot of existing tutorials aren't written for Swift.
One really important thing to note is that even though the languages are different, the underlying iOS/OS X libraries and frameworks are the same. The hard part isn't really learning the syntax of the language, it's understanding how to accomplish what you want. For instance, showing pins on a map or displaying items in a collection view.
FWIW, I teach iOS app development, and I think that beginners should learn Objective-C, not just Swift.
Swift is a replacement for Objective-C in Apple world. But that doesn't mean Objective-C is going anywhere. It has rich ecosystem and experienced developers all over the world. You can create application using both languages simultaneously which allows you to use mature libraries or frameworks in Swift.
Language is a tool. Companies don't hire programmers for knowledge of specified language but for the ability to solve problems.
Senior developers only need Obj-C for now, but should be learning Swift already.