Why are any manufacturers going to drop the $$ to include 3.0 until there is enough demand for it?
You can't find 3.0 included in most computers right now, unless you go and buy your own motherboard or a computer from a very specific niche of the industry.
You need to have market share (or in apple's case mindshare) for consumers to care or be aware of of a product like usb 3.0, which goes way over the heads of the vast majority of such consumers.
Simply put, until 3.0 is prevalent in consumer devices besides computers thus requiring said computers to have 3.0, people aren't going to care or even know what usb 3.0 is.
Again I'd like to note I'm talking about consumers, meaning not computer nerds like us.
Please tell me where the "demand" will come from? Was there a "demand" for USB 2.0? Or was it just a natural progression to a better standard?
We are talking about functionality that is, in general, not a customers number one priority.
Customer: Can my flash drive fit into that slot?
Employee: yes and you have 2 of them.
They would not care about speed, until they have and issue with it. I would venture more important than speed is reliablity.
USB 3.0 will be a standard, if only because it is easily backward compatiable to USB 2.0. That should be enough reason for apple to include it on their next year laptop line.
As of today, I do not think apple will put USB 3.0 in there line next year. Apple is hardly ever a place for new tech to live(unless they create it)