So. Oracle and IBM make nice and agree to support OpenJDK over Apache Harmony. Stephen Colebourne gives a good rundown on why this seems to make sense for IBM, and I have no real reason to argue with his assessment.
There's been grumblings that this is a "Screw Google" move, since Google leverages Harmony in it's implementation of Android, and that this may have a serious impact on the Android platform. There may be some validity to the claim that Oracle is trying to stick it to Google in some way, but I seriously doubt this will impact Android in any real way.
There are two reasons why:
The first is the simple fact that Apache Harmony is open source. There is really nothing stopping Google from just picking up the project and throwing their own resources at it (it's Google...they have no shortage of people they could put on this if they chose to). Given the current lawsuit by Oracle, I'm not entirely sure Google would do this...but it is certainly possible.
The second is that, given that Harmony is licensed under the much more liberal Apache License, rather than the GPL, Google can simply fork the project as they see fit. In fact, I'd bet this is really what they've done for the Android platform already -- Most sources I've read regarding Android mention that parts of the Android platform are based on Harmony, a choice of words that seems to imply that it has been customized specifically to Google's requirements for the Android platform. And it seems to make make sense that Google would do this given both the fact that the Dalvik VM isn't a Java VM (and hence the Harmony code would likely have to be tailored to that VM in some ways) and the fact that mobile devices have constraints that a standard PC doesn't, which is what Harmony was originally intended to run on.
So, unless I'm missing something, I don't see where this will have any serious impact on the Android platform at all. The outcome of the lawsuit by Oracle is likely to have a bigger impact than this turn of events.