Some are speculating that the iPad has already killed off the US market for tablets. According to Matt Burns at Crunch Gear, that may be the case.
Burns cites the Amazon's Kindle and Barnes & Noble's Nook as two prime examples of devices taking complete control of a market. However, in continents like Europe and Asia, he explains that there are several models of ebook readers available. Given, here in the States we have quite a few choices, there are only two readers that truly have control of the market while the others may as well throw in the towel.
More importantly, he mentions a concern that Apple may have done something similar with the iPad. Many companies would be reluctant to spend the development and research money that goes into creating any sort of tablet computer. Especially if that means competing with the iPad, which has already become the device that comes to mind when people think tablet computer.
We will add our personal anecdote to Burns' conversation: While calling some stores (admittedly none were focused solely on consumer electronics) about future availability of an HP Slate, most employees seemed a bit puzzled until we said, "It's like an iPad, but made by HP," it was as if it had suddenly become clear to them what we were asking for. Most had never heard of it.