Much speculation has been prompted by the photos from last week that showed Apple referring to their computer operating system as “OS X Leopard” instead of the previous “Mac OS X Leopard.” Some have theorized this is indicative of Apple licensing their OS to other computer makers.

In other words, OS X (the software) will run on something other than a Mac (the hardware).

I don’t recall anyone saying this is a slam-dunk, no-doubt expectation for tomorrow. In fact, John Gruber and Dan Benjamin spent a healthy portion of the most recent episode of The Talk Show shooting this rumor down. Basically, Apple makes way more money on a $2000 computer than they do on a $129 box of Leopard, so why would they screw up the revenue stream.

I agree with this. Apple will not license OS X to run on other companies’ non-Macs. But it got me thinking.

What if Apple is going to build something that does run OS X but is not a Mac?

Now, it’s been nearly 25 years since Apple built computers that weren’t Macs, but they have done it before. I don’t think they’d produce a normal desktop or laptop computer and call it not a Mac, but maybe they have something entirely different to surprise us with.

There’s been a persistent rumor of Apple working on a “tablet” Mac, either a full-blown, Leopard-running computer that fits in your hand or an oversized iPod Touch running “OS X iPhone.” I think it’s possible this could be the computer-but-not-a-Mac (CBNAM) I’m thinking of. That said, I don’t think this is a particularly likely announcement for WWDC tomorrow.

So, bottom line, I don’t have a great answer for what this CBNAM could be, but this line of inquiry interests me. I think most of the other expectations for Steve’s speech, while exciting, are relatively fleshed out.

This not-Mac could be how Apple surprises us tomorrow.