I understand the frustration (I do find the integration to be a work in progress and often clunky), but it's an overstatement to say that there's "no integration" at present. While it's true that if you had a Kindle DX on your left and an iPad (or some other 10.1" tablet) on your right, you could do many of the same things (although I suspect that you would find it more cumbersome). Of course, those two devices individually are around the same cost of the eDGE, so you'd be well beyond the $500 price point if you were going to go the two gadget route.

At present, there is no device that does the full range of what the eDGe can (or soon will be able to) do for $500. There are many devices that do individual functions better, but nothing that does it all in a single, $500 package.

EDIT: Of course, with a combined Kindle DX and iPad, you still wouldn't have the annotation capabilities on the eInk that the eDGe has, which for me would be a deal breaker.