I'm not sure if anyone has come across this yet but Arduino 11 will not launch when Java 6 is the default JVM on Mac. The error is as follows:
Cannot launch Java application Uncaught exception in main method: java.lang.UnsatisfiedLinkError: /Applications/arduino-0011/Arduino 11.app/Contents/Resources/Java/librxtxSerial.jnilib:
Switching to Java 5 makes everything ok. From what I have read this is because Java 6 is 64bit only and requires all native libraries to also be 64bit.
To avoid this error in future releases it might be an idea to change the Info.plist JVMVersion property from 1.4+ to 1.4* That way rather than the latest version being used, the latest version of 1.4.x is used.