It's like saying a new Mercedes is the "BMW killer." Some people just prefer BMW (or insert your favorite car here).
The problem with the automobile analogy is that the market for computing devices is very different.
A BMW can use the same roads as a Mercedes. It uses the same fuel, can be parked in the same spaces. If you know how to drive a BMW, you don't need much training to drive a Mercedes. They can be sold by the same people, and can be serviced by the same mechanics. And if 99% of the cars on the road were made by BMW, Mercedes owners wouldn't really notice much difference.
This ISN'T true with computing devices. Because they rely on software and, generally speaking, software written to run on one device WON'T run on a different system.
So far, Apple is handily winning the software battle in the tablet marketplace. Apple has persuaded developers to create tens of thousands of Apps designed to take advantage of the iPad's screen size, sensors, touchscreen, etc. Google HASN'T. And at this point, I'm not sure that Google, or RIM, or even Microsoft will be able to catch up.
The process of creating the App-ecosystem is sort of a "chicken and egg" scenario: Developers won't write Apps unless there are millions of potential customers. And its very hard to get millions of customers if there aren't many Apps for the device in question.
Apple created a somewhat unique situation for itself: It created the first "App Store" (for the iPhone and iPod Touch) that gained widespread acceptance by both customers and developers. Apple also developed enough trust with the developers, as well as confidence among them that Apple could sell millions of iPads, that developers were willing to invest money writing Apps before the first iPad went on sale.
Google and RIM and Microsoft are coming very late to that game. And until they figure out a way to seriously challenge Apple at the App-ecosystem game, then all this talk about tech specs and "iPad-killers" is just so much hot air.