Just out of curiosity, I wondered what scientific papers look like on the Kindle DX's 1200 x 824 pixel resolution. The native PDF support is great, but exactly how readable are those tiny little subscripts in mathematical formula?
Although it will probably take some time until I can lay my hands on a real device, I did the test by scaling a page of one of my own papers to the Kindle's resolution. Check for yourself by clicking on the thumbnails below.
(full page zoom: page fits within 824 x 1200 pixels)
(width rescaled to 1200 pixels)
In portrait mode, some details might be difficult to distinguish, especially when the PDF is generated from a scanned image. Check for instance this formula, from the scanned version in portrait mode:
But in landscape mode everything looks perfectly readable (at least in this probably very unrealistic experiment). This is the same formula, as it appears in landscape mode:
So I might buy one when it's launched in Europe. But the price needs to be slightly lower. $300 (or its equivalent in €) would be fine. And it needs an SD slot. And Wifi. Apart from that it seems to be fine.