Java SE 7u15 is the latest release by Oracle, OS X is still with Java SE 6?
No, you can download Java 7 for OS X from oracle.com just like you can for other OS. The reason people are talking about Java 6 is that Apple also compiles their own version of Java and it is part of the default distro. But this is a legacy from when Sun/Oracle didn't make Java for the Mac so Apple did it themselves. Now that Oracle does it, I'm sure Apple will remove their Java in the next release of OS X.