Last time I checked WWDC does not have the word "Mac" in it. Worldwide Developers Conference. This one was simply about iOS and iPhone.
You are correct, WWDC is a generic title. However, as it is the only major conference now held by Apple, it should encompass all that they do.
iOS is clearly where it is at just now and that has been recognised at this WWDC. However, it is the developers that worked solely on OS X that helped Apple to reach the situation they now find themselves in. iMac was only part of their rise back to success. The software that was then developed for it was a major player. Sure, there will be a vast number of them now developing for iOs... but not all of them. Will we see Quark for iPad, Photoshop et al, Final Cut etc etc?
WWDC is Apple's stage to doff their cap to these people and show of the shiny new, more powerful kit that will help drive sales of their work. For most of us it is pure eye candy.
As others have stated on this discussion, Apple also axed some of the developer awards. These awards can be mega important to the smaller developer and can drive sales that bring the revenue in to support future development of the OS X version and can lead to development of iOs versions, where suitable.
WWDC has had this tradition for a good few years. All of a sudden it ignores all that and focuses almost entirely on iOS.
WWDC also has an entire eco-system surrounding it. Macrumors is a perfect example.
I think the new iPhone is an excellent example of why a 'Mac' event is rather important.
We all thought we knew what Jobs was going to show us when he got on stage. We had all seen the iPhone 4 a week or two in advance. However, Jobs nailed it with his comment that we haven't REALLY seen it.
His near 2 hour keynote gave us the real reason to go out and buy one. There is no better salesman than Jobs. He could sell iSand to the Arabs.
Personally, i would be quite happy to listen to Jonathan Ive introduce his next magnificent design. I love his deep and meaningful chit-chats. But, i fear his approach will not have that 'Boom' effect. He can't reuse the '... but there is one more thing' line. That will only work for Jobs.
Will new 'non iOS' equipment just appear on the Apple Store from now on? Will it just be a snazzy picture with a few pages of text telling us why we need it? I hope not. Nowhere near as much impact as Jobs doing the demo on stage.
Oh.... there is one more thing.
Maybe consider hosting this second WWDC outside of the USA. Bring it to Europe.