In Java SE 7 Update 21 Release and more [1], Tori Wieldt [2] pointed out that "Oracle has released three updates to Java" this past week: Java 6 Update 45 [3], Java 7 Update 21 [4], and Java SE Embedded 7 Update 21 [5]. This The Java Source [6] blog post briefly focuses on "new security features in this release" (more than just security fixes [7]): "new Server JRE package [8]" (tools used commonly for server "without the Java plug-in, auto-update or installer found in the regular JRE package"), removal of low and custom settings from Java Control Panel [9], and changes to Security Dialogs [10]. Markus Eisele [11] has posted additional details on the new security features in Java 7 Update 21 Security Improvements in Detail [12].
Whether it be security fixes or security features, the attention paid to security in Java SE 6 and Java SE 7 has come at a price [13]: it looks like Java 8 is likely to be delayed again (this time pushing General Availability [14] to First Quarter 2014). In the blog post Java 8: Secure the train [15], Mark Reinhold [16] writes, "Maintaining the security of the Java Platform always takes priority over developing new features, and so these efforts have inevitably taken engineers away from working on Java 8. ... As a consequence of this renewed focus on security the Java 8 schedule, with a GA release in early September, is no longer achievable." For people waiting to upgrade from Java 6 to skip to Java 8, this delay of Java 8 is another reason to consider upgrading to Java 7 now.
Although Oracle has been warning [17] of the end of free availability of Java 6 updates [18] since the beginning of the year and extended Public Updates [19] multiple times, Henrik Stahl [20]'s post Oracle JDK 7u21 released with new security features [21] states that "we are not planning any more public JDK 6 updates" (past Java 6 Update 45). Users of Java 6 are encouraged to migrate to Java 7 [22] to continue receiving public updates. In his Question-and-Answer formatted post, Stahl also covers alternatives such as access to newer Java 6 releases via the appropriate support license ("Oracle middleware or applications customer") or via separately purchased Java SE support [23].
[24]
Besides access to future public releases of Java SE, there are other reasons to upgrade to Java 7. Some of these are enumerated in 7 reasons to upgrade to Java 7 [25] and the "Features of Java 7" section of "Why should I upgrade to Java 7? [26]"