How disruptive will Google's (NASDAQ:GOOG) Chrome OS be? We'll know more today, when executives show off a demo of the operating system at a press event at the company's Silicon Valley headquarters.

The promise of Google's operating system is intriguing. Chrome is to be open source, lightweight, and an efficient gateway to cloud computing applications. Like "Cloud" from Good OS, but on steroids you might say.

And since Chrome is from Google, we're expecting a lot. We're expecting today's demo to be at least worthy of downloading to Dell (NASDAQ:DELL), Hewlett-Packard, and Asus netbooks. We're expecting it will work well enough to want to see more.

Unfair, you say? Probably, but Google is the one proposing that Chrome OS will be a game-changer and, as investors, we're expecting to see game-changing news.

Why we might not
The trouble with such expectations is that few companies ever meet them, and Google has as much a track record for failure as it does success. Apple (NASDAQ:AAPL) is a rarity in this sense.

Let's also remember we're talking about a huge project here: a computer operating system. This is new to Google -- the archivist has become the creator. With Chrome, its engineers will be responsible for everything from basic printer drivers to software and Web interface design. Just writing that gives me the shakes; I can't imagine the late nights coders are enduring in Mountain View.

But thanks to the open source movement, much of the needed code might already exist -- which doesn't necessarily erase the magnitude of the project. Getting an operating system right is tough business. Ask Apple, Microsoft (NASDAQ:MSFT), or Red Hat (NYSE:RHT) what they think.

When code doesn't catch on
How much is too much to expect four months after a press release? A game-changing software release that's still very much in development would be my guess, especially since we've seen ambitious operating systems come and go before.

Anyone else remember the BeOS? The company founded by former Apple executive and current venture capitalist Jean-Louis Gassee foundered after the Mac maker purchased NeXT in 1996, returning Steve Jobs to the company he co-founded.

Thus it was NeXTSTEP, rather than Be, which became the foundational component of what today we know as Mac OS X. Be lives on as the open-source Haiku operating system.

Watch out for the "e" word, Google
Engineers have long memories, and you can bet that the coders at Google HQ are working overtime to make sure Chrome isn't the next Haiku. But to avoid that fate, The Big G is going to have to do more than make its OS functionally ready. Chrome is going to have to be attractive to developers. It's going to need an ecosystem.

I'll understand if that sounds strange. As a cloud-computing operating system, Chrome's ecosystem is, essentially, the Web. Every bit of software built for the browser is therefore built for Chrome. Except that it isn't that simple. Not all browsers read and present data in the same way. Microsoft's Internet Explorer isn't built for HTML5, for example.

This is why you're seeing Google embed the Chrome browser's WebKit rendering engine everywhere it can, including inside IE. The more users that adopt Chrome's engine, the fewer issues there are likely to be.

Indeed, it's no accident that the browser and the OS share the same name. Rather, the choice is reflective of Google's view that the browser is rapidly becoming the new "runtime" for applications. A runtime is a system that executes code so that software can function. Adobe's (NASDAQ:ADBE) AIR is a runtime.

Still confused? Think about how you use (NYSE:CRM). A distant server hosts the software, sure, but there's also Javascript code that executes in the browser.

A more polished Chrome
So of all the things I'm looking for in today's Chrome OS rollout, its tools interest me most. Frankly, I don't know what they will be, or even what they should be. What I do know is that big, hairy compatibility issues could kill Chrome before it has a chance to live.

Good tools, on the other hand, could unite Web developers to Chrome early and keep them loyal. This chance is too important to miss.

But that's my take. Now it's your turn. Do you think Chrome OS will disappoint? Or will Larry and Sergey score a first-round body blow with today's events? Tell us what you think by voting in the poll below. You can also leave a comment to explain your thinking.

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Fool contributor Tim Beyers had stock and options positions in Apple and a stock position in Google at the time of publication. Check out Tim's portfolio holdings and Foolish writings, or connect with him on Twitter as @milehighfool. The Motley Fool is also on Twitter as @TheMotleyFool. The Fool's disclosure policy would like very much to have something funny to say here. Who's got a joke to share? Anyone?