I'm seeing that the methods with signatures expect(Object...) conflict with the ones like expect(int, Object...)
I'm seeing this while working in Eclipse. I know that type ambiguity resolution rules for Java are a bit confusing, so I'd recommend for clarity that you not use a varargs Object, instead using specific types for what you support (String... and Pattern...).
I know this loses the ability to put both Pattern and String objects in the same method call, but how often is this actually done? I'd say this is less important that the use of specifying a custom timeout per expect() method call.