On 8 November 2011, Apple released a pair of Java 6 updates for Lion and Snow Leopard.
The new updates aim to patch vulnerabilities increase the reliability and compatibility.
Java 6 Update for OS X Lion has the size of 62.53 MB. Apple claims that this update increases reliability and compatibility, in the words of Apple.
Java 6 Update for OS X 10.6 (Snow Leopard) has the size of 75.45 MB. In the words of Apple, this update makes your Mac more safe and secure.
In a support document released with these updates, Apple said that both updates will fix many of the bugs that Apple users were complaining about.
Source: Mac Rumors