Does SQL Developer 4.0 support the 64-bit JDK 7 (http://download.oracle.com/otn-pub/java/jdk/7u25-b17/jdk-7u25-windows-x64.exe), or should I be downloading the 32-bit JDK 7 (http://download.oracle.com/otn-pub/java/jdk/7u25-b17/jdk-7u25-windows-i586.exe)? I discovered the hard way that SQL Developer 3.x only supported the 32-bit JDK 6, even though I'm running on a 64-bit Windows 7 desktop. I never did find any official documentation about this limitation for SQL Developer 3.x -- only various discussions that I found on the web. Likewise, I see no clarifications about this in the official documentation for SQL Developer 4.0. Thanks.
Much obliged, Jeff. I marked your answer as correct. Thought I had trouble with the 64-bit JDK with SQLDev 3.x, but it's possible I'm confusing it with some other incompatibility. I even found a blog post (Oracle SQL Developer unable to find Java Virtual Machine) that mentions such an incompatibility. But no matter. I won't be trying a 64-bit JDK with SQLDev 3.x again. I'm planning to just charge forward with a 64-bit JDK with SQLDev 4.0 and see how it goes. Thanks again.
Thanks again, Jeff. I installed the 64-bit JDK 7 and SQL Developer 4.0 Early Adopter and all is working fine so far. It's possible I was confusing this whole non-issue for SQLDev with the very real incompatibility that I experienced with the 64-bit Oracle Data Access Components and my Microsoft Office 2007 software, which is 32-bit. I spent a fair amount of time troubleshooting and Googling before finally figuring that one out. Maybe I then stuck with 32-bit for all Oracle related software after that experience, but I honestly don't recall what my thought process was at that time. Anyway, case definitely closed on this post.