We've got to hand it to Steve Jobs and his Mighty Iron Fists of Silence; here we are, just a few hours away from his Macworld Expo Tokyo keynote address, and our instruments are registering abnormally high uncertainty readings from the Mac grapevine. Normally by now, last-minute details about Steve's new Macs would be plastered all over the 'net, but instead, all that we've found are what appear to be educated guesses that your average fourth-grader could have pieced together after listening to Apple's last earnings conference call. Evidently the more blatant leaks in the Silicon Curtain have been patched, and all the little worker bees are keeping their traps shut. (Apparently Apple's recent punishment-for-leaks policy change from "immediate grounds for dismissal and potential litigation" to "immediate grounds for dismissal, extended periods of Inquisition-style torture, a savage beatdown by the lawyers, and a slow, lingering death" is paying off.)

The apparent lack of cold, hard facts hasn't stopped AppleInsider from keeping us up to date on the imminent iMac revision, though. The latest skinny is that the low-end iMac will keep its basic CD-ROM drive, the mid-range units will move to an iTunes-friendly CD-RW drive, and the top-of-the-line Special Edition "will sport a DVD/CD-RW hybrid drive." (Note: that's not the same thing as the SuperDrive, which is currently only available in the 733 MHz Power Mac G4. So you'll be able to watch DVDs on your new iMac DV Special Edition, as well as burn your own CDs, but don't expect to be cranking out the Great American Movie using iDVD on an iMac anytime soon.) In addition, all models are expected to feature "much faster PowerPC G3 processors" (now that the G4 has finally upped the megahertz ceiling to 733 MHz), with a slim chance of a G4-based iMac making its debut. Nothing we haven't heard before.

Meanwhile, AppleInsider is conspicuously quiet about the second of Apple's "couple of new or revised hardware offerings"; in fact, that quote is pretty much the only reference we get to any potential non-iMac hardware updates. Mac OS Rumors doesn't offer much more, but at least hints that updated iBooks are a slim possibility-- though that prediction is based entirely on the public interview with Apple's European Education Director we referred to yesterday, instead of any juicy insider info smuggled out of One Infinite Loop. Yes, folks, when it comes to rumors based on honest-to-goodness leaks, the well's a-runnin' dry.

But hey, at least we can all look forward to the element of surprise. And those of you lucky enough to have satellite dishes can even watch Steve strut his stuff live; as faithful viewer Kris Hansen pointed out, Apple has posted the satellite coordinates for the keynote address. Let us know how it all turns out; being dish-disabled, we'll reserve our "oohs" and "aahs" for the press releases after the show.