NetBeans IDE under Oracle
Oracle have put a lot of time and money into their own product, JDeveloper. It has some pretty neat features. But it has never got much traction in the industry, because many Java developers don't like using proprietary software, even though Oracle make quite a big play over their commit to open standards.
Anyway, at the moment Oracle are still integrating a lot of their freshly acquired BEA WebLogic functionality into the JDeveloper suite. But I'm sure that once they have sealed the deal to buy Sun they will start to look at what they can take from NetBeans. Because whatever you may think about Larry Ellison's business methods, he knows the value of a dollar. If there are things worth having in NetBeans, they will not be thrown away, they will end up in JDeveloper.
edit
So you say it will abandon NetBeans and salvage some pieces which will go into JDeveloper?
In the long run Oracle will not maintain two Java IDEs. But look at their strategy for handling previous acquisitions (Seibel, JD Edwards, BEA, etc). Oracle have kept those products current while they devised a plan for getting the customers onto Oracle's own brand applications. In some cases this meant dumping Oracle's offering in favour of the acquired product (Seibel Analytics, BEA WebLogic Server).
Oracle has made similar sounding pronouncements with regards to MySQL. People may scoff, but I think Oracle will keep MySQL going, partly because Larry thinks they can make money from it but also just to spike Microsoft's attempts to swipe the MySQL customer base.
I haven't read anything official regarding Oracle's intentions for NetBeans. So the following is just my conjecture. Oracle won't kill off NetBeans. If it did that then all the NetBeans users would probably decamp to Eclipse (because many people share Pascal's belief that "JDeveloper sucks"). Indeed Oracle will probably keep it going for some time yet.
In the meantime they will create an inventory of the features in NetBeans which are better than the JDeveloper equivalent or which have no equivalent, and which can support Oracle's Fusion programme. For instance Ellison has been vocal in his admiration for JavaFX. My uninformed feeling is that it will be easier to port that functionality into JDeveloper than it will be to reverse the Fusion stuff into NetBeans. I might well be wrong about that. Perhaps it would make more sense to leverage NetBeans' broader market penetration and cut JDeveloper loose.
Either way I think you should start working with NetBeans, because that functionality isn't going to disappear overnight.
update
InfoWorld has just (27-JAN-2010) published a summary of Oracle's plans for Sun. The pertinent bit is
NetBeans, the Sun-driven open source Java IDE that has competed with Oracle JDeveloper and the Eclipse platform, will remain as a "lightweight development environment for Java developers," Kurian said. But JDeveloper continues as Oracle's enterprise development tool.
I was a long time eclipse user, and although I still like it for some things, I believe Netbeans to be a far superior IDE for Java development. I would say go ahead and use NetBeans. You will appreciate it more than Eclipse. In the worst case scenario that Netbeans is no longer supported, you will be a much better developer by the time it has reached its end of life (i dont think this will happen though).