Reusable configuration reader for Java
Two things which are good to know about JAXB:


You can annotate private methods and fields, JAXB can call/modify them. It could help hiding internal data structure from clients.
Marshaller as well as Unmarshaller has event callbacks. They can help handing deprecated or compound fields.


Just two small notes about the code:


I would call the class JaxbConfigurator. Lowercase letters are easier to read. (Effective Java, Second Edition, Item 56: Adhere to generally accepted naming conventions)
It would be worth checking input parameters in the constructor to avoid latter mysterious NullPonterExceptions:

import static com.google.common.base.Preconditions.*;

...

public JaxbConfigurator(final Class&lt;T&gt; toConfigure, final String xmlFilePath) {
    this.clazz = checkNotNull(toConfigure, "toConfigure cannot be null");
    this.filePath = checkNotNull(xmlFilePath, "xmlFilePath cannot be null");
}