Wasn't Samsung making the original displays for the iPhone, and the iPad?
I agree that in some instances Apple is able to leverage it's large bank account to get exclusives and lock others out of the hardware. If memory serves me correctly, they purchased an enormous amount of flash memory before the release of the iPhone, and though flash memory was available to other manufacturers, there was a significant jump in the price of flash memory.
I think a larger factor has to do with Apple's ability to design hardware and software in parallel.
Other manufacturers wait until the software is nearly complete before getting developer builds which they build hardware around.
I suspect that the time from going from developer release to public availability is 8-15 months at the moment.
If these times could somehow be brought down, we'd see more competitive products to market earlier.
Let's not forget that everybody was showing tablets at CES before Apple announced the iPad (even though we all suspected it was going to happen), and yet competing devices didn't show up for nearly 10 months after the iPad was released.
