I am hoping two things happen:
1. Apple contributes their Java modifications for OS X to OpenJDK (open sourcing the modifications)
2. Oracle (or some other competent entity) takes over maintaining the OS X version of Java
We don't know whether either of those two things are going to happen yet. Oracle has not made a statement on whether they will pick up maintenance. It seems like they would obviously want to, but until they make a statement, we just don't know. I'm sure that Sun would have. According to Gosling, Sun was willing to do the OS X version, but Apple insisted on doing it themselves. But this is Oracle and we are already seeing them abandoning many of Sun's projects, so who knows what they are going to do.
I'm a developer who just got comfortable using OS X as my main platform over the last 2 or 3 years. 75% of the code I write is Java. So I am concerned about the outcome of this. Sure, I can move to Linux if things go south, but I am completely happy with OS X and don't want to be forced to switch. Fortunately, the main Java GUI app I use is Eclipse, which uses SWT which could probably run fine on something like Soylatte, but still there are a number of Swing apps I use. And all of the Java code I write is server-side, so something like Soylatte could work. But I'd rather have a well-supported official JDK to depend on, and not have to use X11 for Swing apps.
Those saying that Java is dying or is "niche" are absolutely clueless. Java is the most widely deployed language currently. The JVM itself is hugely popular and is being used for new languages. Java the language is being used for new libraries and products such as GWT and Android. For better or for worse, Java is here to stay for a very long time.
This is mostly a concern for developers, but that doesn't mean it's not important. The idea that people developing using Java just use Windows is just false. The company I work for develops enterprise software in Java. We are all using Macs. OS X is closer to our deployment platform (Linux / Solaris) anyway. When I go to Java User Group meetings I see more and more people are using Macs now. When I go to a dev conference such as Barcamp, *most* people are using Macs. OS X has become a development platform of choice by a huge number of people. To make it less appealing in this way would be a mistake.
Of course, we will have to see how this plays out. The end result may not be bad, it may even be an improvement, but there is uncertainty right now. Apple's been slow about Java releases (especially 1.5, but even Eclipse was slow to support that), but better to be slow than to have no one develop Java for OS X. We'll see...