Yesterday's WWDC conference may have mixed reviews but one of our engineers and I had the chance to attend and I was struck by a few things in listening to Steve give his keynote.
Release frequently
The last few "Stevenotes" have compared just how many OS releases there have been for OSX compared to Windows. This reinforces not only that Apple continues to innovate but that they're listening to people and responding vs. the epically long releases from Microsoft.
Keep it simple
Yesterday, at the end of Steve's speech on Leopard, he disclosed each edition of the OS and it's respective price. Basic edition: $129. Premium: $129. Business: $129. Pro $129. Enterprise: $129. Ultimate: $129. This was an obvious poke at Microsoft and all their ridiculous OS editions and prices. The subtext: We treat you with respect.
Make something painful, exciting
Steve showed a lot of cool things, but the one thing he showed that got my attention was Time Machine. I think this feature will attract a lot of Windows users. In essence Apple is making backing-upthe ugliest, scariest most denied part of computingactually sexy and fun. With Time Machine, when you can't find something and have that moment of "oh uh," you simply click on Time Machine and literally go to a new interface that looks like you're in the Millennium Falcon. When you search for something, you zoom past screens of time until you find it. Then simply restore it. In essence, Apple is turning the fear and pain of file loss into something fun. Brilliant.

There were many other cool announcements like the ability to go deep into viewing the contents of files without launching applications (Quicklook). But most obvious is Apple's vested interest in increasing it's stake in the browser market with their announcement of Safari for Windows. I'm not sure how bundling Safari with iTunes will give Safari market share. I had hoped Steve would also announce Safari was now open-source or at least have plug-in support (it is very standards-based). My guess is that Apple expects to sell enough iPhones to lure Windows/Apple developers to make lots of iPhone apps (since they have to be delivered through Safari) and that's Apple's road to browser marketshare and even more Apple developers.

Safari is actually a good example of Open Source and proprietary co-mingling. Safari makes liberal use of code from the Konqueror web browser from KDE (Webkit), of which is all Open Source. In turn, Apple releases many of its changes back to the developers. While not all changes make it into the upstream, many certainly do. WebKit is its own project (http://developer.apple.com/opensource/internet/webkit.html).
The part of Safari that isnt OpenSource is the interface and some other features. While it certainly would be nice to see that open up, I dont begrudge Apple for keeping some things for themselves.
I do agree with you, though, that some form of plugin/extension support would be nice. I might give up Firefox completely if that were to happen.