I've been in contact with the author of Mangle the past couple days awaiting my DX, and compiled a one-off Kindle 2 DX version taking advantage of the 824x1200 resolution which can be downloaded here:
http://foosoft.net/mangle/downloads/MangleWindowsPreview.zip

The main page is here:
http://foosoft.net/mangle/

It is AWESOME. You can see some examples here, click for super high resolution.

http://www.christopherwu.net/albums/kindle/mangle_dx_watchmen.sized.jpg (http://www.christopherwu.net/gallery/kindle/mangle_dx_watchmen?full=1)

http://www.christopherwu.net/albums/kindle/mangle_dx_watchmen_closeup.sized.jpg (http://www.christopherwu.net/gallery/kindle/mangle_dx_watchmen_closeup?full=1)

More examples here:
http://www.christopherwu.net/gallery/kindle/

w00t!!!

For the curious here are the options I used:
http://www.christopherwu.net/albums/kindle/mangle_dx_options.png

...if you downloaded this program yesterday, go back to Alex's webpage and redownload it again. I did some messy hacks to his code to hard support other features such as 256-grayscaling (for size, K2DX's dithering isn't half bad looking and quick) and all of the default settings are now my recommended settings after testing it around a bit. Also the image is scaled down AND up because the zoom on the K2DX is very clunky right now between pages and books. Thanks again to Alex for hosting my temporary build of this K2DX before he gets around to optioning everything correctly in his program.

http://foosoft.net/mangle/downloads/MangleWindowsPreview.zip

unrequited-- I'm curious if you know if the Kindle (DX) browser can open zip files within it (for the purposes of a LAN manga server so you don't have to load them via USB)?

No clue but I'll try to test that later today unless somebody else can chime in sooner.

I've just tried this program and I prefer to select all images and send them to a virtual printer. In Windows and with CutePDF it is almost immediate. And then if you rotate your DX, you will get a zoom.

I've tried this program and it works well.

There are a few oddities that are probably due to the DX rather than the program.

Your place is not held when you exit the book. I will try the PDF method mentioned by rfog to fix this. Also, some pictures take a long time to load (5 - 10 seconds) while others are almost instant. The responsiveness doesn't seem to be based on the complexity of the image. Lastly, upon waking, the DX chokes on the picture -- you have to press the down key for the next page for it to start up correctly.

Update: It appears that the problem with the long load times is corrected by turning dithering off -- I can't tell the difference between on and off -- and using full screen mode. Also, for some reason my place is being held fine now.