He descargado la última versión de Java del sitio de Oracle y la he instalado en mi mac.
MacCris:~ cris$ java -version
java version "1.7.0_11"
Java(TM) SE Runtime Environment (build 1.7.0_11-b21)
Java HotSpot(TM) 64-Bit Server VM (build 23.6-b04, mixed mode)
entonces,
MacCris:/ cris$ ls -l /System/Library/Frameworks/JavaVM.framework/Versions
total 64
lrwxr-xr-x 1 root wheel 10 Jan 3 20:20 1.4 -> CurrentJDK
lrwxr-xr-x 1 root wheel 10 Jan 3 20:20 1.4.2 -> CurrentJDK
lrwxr-xr-x 1 root wheel 10 Jan 3 20:20 1.5 -> CurrentJDK
lrwxr-xr-x 1 root wheel 10 Jan 3 20:20 1.5.0 -> CurrentJDK
lrwxr-xr-x 1 root wheel 10 Jan 3 20:20 1.6 -> CurrentJDK
lrwxr-xr-x 1 root wheel 10 Jan 3 20:20 1.6.0 -> CurrentJDK
drwxr-xr-x 7 root wheel 238 Jan 3 20:20 A
lrwxr-xr-x 1 root wheel 1 Jan 3 20:20 Current -> A
lrwxr-xr-x 1 root wheel 59 Jan 3 20:20 CurrentJDK -> /System/Library/Java/JavaVirtualMachines/1.6.0.jdk/Contents
que va a /System/Library/Java/JavaVirtualMachines/1.6.0.jdk/Contents
y ejecutando
MacCris:bin cris$ /System/Library/Java/JavaVirtualMachines/1.6.0.jdk/Contents/Home/bin/java -version
java version "1.6.0_37"
Java(TM) SE Runtime Environment (build 1.6.0_37-b06-434-11M3909)
Java HotSpot(TM) 64-Bit Server VM (build 20.12-b01-434, mixed mode)
Así que el actualJDK es 1.6 a pesar de que instalé el último java.