What is the secret to getting that version (18-b03). On my win7 64bit machine I have build 1.6.0_16-b01 and Sun Java says I have the latest version.
I'll wait for the official release, but I've got 1.6.0_17-b04, which appears to be the latest non-beta version. When I hit java.com on my Win7 machine, it did an automatic update, but only of the 32-bit version. To get the update on the 64-bit version, I had to hit the "see all Java downloads" link, then the "Information about the 64-bit Java plug-in" link, and lastly the "manual download" link.
This page is woefully out of date (it doesn't even mention Win7, or even IE8), but apparently IE defaults to the 32-bit version (there's nothing to be gained by using 64-bit in a browser, I guess), so that's all the java.com version checker sees. I believe FF also defaults to the 32-bit. So, to get an update for your 64-bit version, you have to do the updating manually.