Anyone who's read OSNews a long time probably knows that I'm a fan of Apple products, and I like the iPad, though I don't own one. (I did get one for my mom, though). The iPad's a great device, but it's not the end-all-be-all of tablets. In ten or twenty years we'll look back on the iPad 2 with nostalgia, kind of how we look back on the Apple][ or the Osbourne 1: revolutionary in their time, but pretty pathetic compared to what came afterward. If tablet computers are going to evolve as quickly as their potential indicates, Apple is going to need some brisk competition, and I think a lot of us were hoping that the TouchPad would succeed, and not just those of us with a soft spot for PalmOS.
One thing that doomed the TouchPad was the fact that it was probably rushed into the market. With the iPhone and then the iPad, Apple had the luxury of being able to perfect the device, because it didn't have the competitive pressure, but the iPad is out there selling like mad, and the other tablet vendors feel they can't wait, that they're losing their window of opportunity, so they rush their products, and it shows. But they are losing their window. And they probably do need to rush a little.
Ultimately, though, there will be a market for non-Apple tablets, even if they have to start by competing on price, and gradually moving upmarket as their products become better over time. And Apple has a long history of getting too greedy, controlling, and complacent, which will eventually give competitors an opening.