Should Sun proprietary code used?

Compiling Openfire will give you warnings that proprietary Sun code is being used. As the warning states, the code might be removed in the future. Having proprietary Sun code will also limit Openfire admins to Suns implementation of the JVM, right? Is this something to worry about?

compile:
    [mkdir] Created dir: /tmp/openfire_update_20071112_124808/openfire/work/classes
    [javac] Compiling 553 source files to /tmp/openfire_update_20071112_124808/openfire/work/classes
    [javac] /tmp/openfire_update_20071112_124808/openfire/work/src/java/org/jivesoftware/openfire/sasl/SaslServerFactoryImpl.java:19: warning: com.sun.security.sasl.util.PolicyUtils is Sun proprietary API and may be removed in a future release
    [javac] import com.sun.security.sasl.util.PolicyUtils;
    [javac]                                  ^
    [javac] /tmp/openfire_update_20071112_124808/openfire/work/src/java/org/jivesoftware/openfire/sasl/SaslServerFactoryImpl.java:30: warning: com.sun.security.sasl.util.PolicyUtils is Sun proprietary API and may be removed in a future release
    [javac]     private static final int mechPolicies[] = { PolicyUtils.NOANONYMOUS };
    [javac]                                                 ^
    [javac] /tmp/openfire_update_20071112_124808/openfire/work/src/java/org/jivesoftware/openfire/sasl/SaslServerFactoryImpl.java:49: warning: com.sun.security.sasl.util.PolicyUtils is Sun proprietary API and may be removed in a future release
    [javac]         if (mechanism.equals(myMechs[PLAIN]) && PolicyUtils.checkPolicy(mechPolicies[PLAIN], props)) {
    [javac]                                                 ^
    [javac] /tmp/openfire_update_20071112_124808/openfire/work/src/java/org/jivesoftware/openfire/sasl/SaslServerFactoryImpl.java:65: warning: com.sun.security.sasl.util.PolicyUtils is Sun proprietary API and may be removed in a future release
    [javac]         return PolicyUtils.filterMechs(myMechs, mechPolicies, props);
    [javac]                ^
    [javac] Note: Some input files use or override a deprecated API.
    [javac] Note: Recompile with -Xlint:deprecation for details.
    [javac] Note: Some input files use unchecked or unsafe operations.
    [javac] Note: Recompile with -Xlint:unchecked for details.
    [javac] 4 warnings