
OpenJDK means Java is already open source. So can't be owned(?) Well current version at least. The other risk is a split between open source version and the proprietary.
Question for people: (maybe a rhetorical one): how can a company own a technology that is open source?
Canonical's development of Ubuntu Linux seems to be a possible example of how an open source Java might be managed by Oracle.
Also, Oracle and Sun's goals align well: Oracle wanted to develop the Network Computer (NC) (thin client with apps downloaded) which Java lended itself well to given the independence from NC hardware.
Meanwhile Sun said the Network Is The Computer - where Oracles thin client NCs would utilise computing power and applications from within the network.
Perhaps also Oracle want to take on Microsoft, using Java to compete with .NET and C#
There are even open source versions of .NET / C# in GNU mono. So a company owning an open source technology can work.
Keeping Java license-free may be advantageous: more support from development community. Oracle gets new development "for free" because of open source developments.
Meanwhile the technology is invested in and maintains credibility with corporations (and therefore a good skill) by integrating with enterprise-class Oracle offerings.
Therefore Oracle buying Sun and therefore Java is just a more obvious form of sponsoring a technology, with an exclusive sponsor Oracle though risk is they may take it in wrong direction.
Many open source technologies are corporate sponsored: think Google's Summer of Code, Tigris and Subversion, Canonical and Linux, Google and Linux based Android...