That's the first time I've ever heard Eclipse referred to as "light weight". That doesn't seem right. At all.
They're both superior in different areas--I'd really recommend just trying both for awhile. I'm an Eclipse and IntelliJ person, but that's really only because I didn't care for earlier versions of NetBeans. From what I've seen recently, and the testimonials of people I listen to, I need to give NetBeans another shot.
Both Eclipse and NetBeans are very good IDEs, both more than adequate for professional Java development.
I've been a long-time Eclipse user, but switched to NetBeans a few months back, mainly because NetBeans has very good built-in support for Maven (it recognises Maven projects out-of-the-box and everything works smoothly). To work with Maven projects in Eclipse, you have to install a plug-in and it doesn't work as well as with NetBeans.
NetBeans does seem to use more memory than Eclipse, but RAM is cheap and if you have 2 GB or more it's not a problem.
I prefer NetBeans now, but you really have to just try them both out yourself and see what works best for you.
Besides Eclipse and NetBeans there's IntelliJ IDEA, which is not free, but there is a free community edition. I've never used it for more than small toy programs, but I know some people who do and they like it a lot.
@David: Yes, older versions of NetBeans (older than 6.0) were not that great, but NetBeans 6.0 and newer are really good and have surpassed Eclipse in many areas (in my opinion).
I personally use Eclipse. I tried Netbeans once while evaluating it for J2ME development. Can't say I was much impressed, though I suspect it was my mental inertia for learning IDE shortcuts all over again.
Only thing I personally find cool about Netbeans is that I can run it with the Napkin LAF which is unfortunately not possible in Eclipse (as far as I know)
While I obviously don't know, I think they'll use it as the basis of their Java IDE strategy, seeing as how JDeveloper isn't exactly in the top three IDEs. If they don't, I'm not really sure what they're thinking.
Bear in mind that WebLogic wasn't an Oracle product until recently. And Java is now an Oracle product--so you're really talking about their *other* products, the usage of which *pales* in comparison to the use of Java, WebLogic, and their DB.