How different are Microsoft and Apple's approaches to rolling out a new operating system? Let's compare and contrast how we've learned about Windows Vista and Leopard, the next generation of Mac OS X:

Microsoft: Begins talking up the new operating system years in advance. Drums up enthusiasm for features that it turns out it can't actually implement. Deploys beta versions early and widely. (I've been running Windows Vista as my only OS on my primary work machine for over a year.)

Apple: Says almost nothing about its new OS until well under a year before its planned release. CEO begins keynote speech at which OS is unveiled by saying he's keeping some of the good stuff secret. Gives betas only to developers, and only if they agree not to talk about them.

All of this makes a truly meaningful comparison of Windows Vista vs Leopard impossible just now. In fact, it's impossible to give Leopard a thumbs up or thumbs down; while Microsoft says that Vista is "feature complete", Steve Jobs has basically put us on notice that Leopard is still feature incomplete.

With those disclaimers in mind, a few thoughts on the two operating systems:

Leopard is entertainment

Leopard is almost by definition a minor upgrade compared to Vista. Both Apple and Microsoft released OS upgrades in the Fall of 2001. (Apple's was OS X 'Puma', and Microsoft's was Windows XP.) The difference is that XP is still the current version of Windows, while Apple followed up Puma with Jaguar, Panther, and Tiger. In other words, Apple has a lots-of-incremental-upgrades philosophy versus Microsoft's big-upgrade-once-in-a-blue-moon approach.

Leopard looks to be idiosyncratic and entertaining in a way it's hard to imagine a Microsoft product being. The first major Leopard feature demoed at yesterday's keynote was Time Machine, a back-up utility that lets you step back to earlier versions of your system and files. This is not exactly a revolutionary idea, and in fact Microsoft is planning at least vaguely similar functionality for Vista. But Time Machine's UI, which involves windows flying through space is quirky and fun. (By contrast, Windows Vista has no particular personality other than XP crossbred with warmed-over effects that OS X has had for years.) I'm not saying it's good for an operating system to have a playful side - I know folks who gnash their teeth even at the way Mac OS X Dock icons bob up and down when an application is loading - but it's becoming a defining difference between the two products.

Apple can still get away with security not being a selling point for an OS upgrade. As opposed to Microsoft, which has to introduce castor-oil features like Universal Access Control. No wonder Leopard looks like more fun than Vista. But you've got to wonder if Apple will be able to stay smug about security forever.

Web services - bot quite yet

Neither Vista nor Leopard shows signs of being truly web native. I'd say it's a dead certainty that we'll eventually see operating systems that are so tightly integrated with web services that you can't tell where the operating system leaves off and the web service begins. But Windows Vista seems to have almost nothing to do with Microsoft's Windows Live services, and if Apple has big plans for better melding of Leopard and the .Mac service, it's keeping them under wraps. (.Mac, which charges $100 a year for stuff that's increasingly available for free elsewhere, is in danger of becoming irrelevant.) You begin to wonder whether some other company (maybe with initials like G.O.O.G.L.E.) will be the one that builds the first real web operating system.

Web clips are potentially a revelation. And a wonderfully webby one at that. This new Dashboard feature - which lets you grab bits and pieces of webpages and store them a keypress away from your desktop - is the best ad I've seen yet for widgets, gadgets, or any other form of little web-enabled applet. (Anybody else remember services such as Octopus, which tried to do similar things a few years ago, before the technology was quite there?) Microsoft's Sidebar and Gadgets, meanwhile, mostly seem to be playing catchup with stuff that's already out there, although the Windows Sideshow mini-screen for notebooks is a potentially interesting feature which we probably won't see on MacBooks anytime soon.

VoiceOver awes

But VoiceOver was the most impressive demo. I've been listening to text-to-speech software since about 1980, and VoiceOver bowled me over - never have I heard a computer come so close to sounding like a person. Great news for folks who can't read a computer screen, but I could see myself multitasking by listening to web pages while doing something else online or offline.

Apple still has the opportunity to surprise us with cool new features for the holidays; Microsoft probably doesn't. The fact that Microsoft has to deliver functionality through third-party PC manufacturers means that we'd probably know about any major changes to Windows as an entertainment platform timed for this Christmas (although the Zune "iPod killer" will presumably have a PC angle). But Apple might still release some Macs with more video and audio stuff, based on Tiger rather than Leopard. In fact, it seems a dead certainty that the iPod-Mac entertainment platform will evolve quite a bit before the year is over.

That's enough random musing for now. I'm about to update my Vista installation to the latest version, and once I do, I'll report back with more thoughts on where Vista stands...