Then, there's Amazon. It has been rumored all year that Amazon is developing its own Android tablet, and many pundits have put their money on Amazon as the tablet competitor finally worthy of going toe to toe with the Apple iPad.

Thanks to MG Siegler of TechCrunch, we have a pre-production prototype. Siegler says the 7-inch device runs a proprietary Amazon fork of the Android operating system, and is expected to retail at $250. For all of the hype and expectations, though, this device sounds like it is designed to go head to head with , not the iPad 2.

Amazon , but I am not sure it will dent iPad 2 sales. The people who will buy the new Amazon Kindle Android tablet probably already own an iPad. In my house we have an original iPad, and an iPad 2, and a second-generation Kindle, and a third-generation Kindle because the iPad and the Kindle are both great devices that have some minor overlap, but don't directly compete with one another.

The reality is that the iPad has no competition right now. All of these rivals are in a cage match to the death...for second place. They can launch new tablets every other week and have cutthroat price wars with each other. While these tablet competitors "ship" hundreds of thousands or millions of tablets, actual --tens of thousands for a "great" tablet.

Meanwhile, analysts estimate that Apple will (including both the original iPad and the iPad 2) in 2011. Not "ship", sell. Apple isn't slashing its price or offering rebates either. Apple can barely produce the tablets fast enough to keep up with demand, while the rest of the tablet field is engaged in a vicious battle for a fraction of the market that represents a drop in the bucket to Apple.