I don't think so. The WWDC presentations yesterday still contained only a fraction of demos for what's coming in iOS6. If things were bad, I don't think they would have added so much.
I understand how people can think this, seeing how the Mac Pro lacks a compelling update, but Apple seems to have its own mercurial schedule these days. Just when you think they've forgotten or ignored something, BAM!, they announce a big change.
Still to come is a new iTunes and improved store discovery. Neither of these are small things.
And iOS still has many strong apps Android doesn't. The real challenge will be what happens when Windows 8 tablets start showing up and devs create for it.
I'm not sure I share your enthusiasm for Windows 8. I tried a rough beta awhile ago and it was pretty bad (that's coming from a guy that grew up on Windows and didn't switch to Mac till 2007). And even then I still use Windows for development testing here and there.
That said, the thing that really nails it for me, and I suspect many others (putting aside development reasons), is the integrated experience. I love the fact that my iPad, iPhone, and Mac work with each other, etc... And once you're in that type of environment, and you have money invested in Apps, etc.. its incredibly difficult to want to move away especially when the experience is great (we can argue the semantics of what constitute as great but lets keep it simple and say good enough for most people).
The move from Windows to Mac was not a difficult one (at least for me). There was no integrated environment and as far as software, new software releases come out all the time so an upgrade or new purchase was going to happen sooner or later. I suspect that a lot of adopters that will be adopting Windows 8 will most likely be existing Window users. They will still dominate the shares in volume but I suspect new Apps on Windows at this point will be a challenge getting Mac users to switch off.
For most people, Windows 8 is really an unknown. I've seen videos and read posts, but until it's out and can be handled, it's all like a movie trailer to me. Android hasn't gained the tablet traction of iOS, so maybe Windows 8 will. It still has very large number of devs.
I understand how people can think this, seeing how the Mac Pro lacks a compelling update, but Apple seems to have its own mercurial schedule these days. Just when you think they've forgotten or ignored something, BAM!, they announce a big change.
Still to come is a new iTunes and improved store discovery. Neither of these are small things.
And iOS still has many strong apps Android doesn't. The real challenge will be what happens when Windows 8 tablets start showing up and devs create for it.