Photojojo recently announced that it was selling iPad CF and SD Card Readers which are designed to quickly transfer images from a DSLR to an iPad. These readers are to be plugged in the iPad, causing its photo applications to open, allowing the image files to be uploaded.
There are some caveats...the maximum capacity for the CF and SD cards is 4 gigabyte. The adapter will not work with any cards over 4gb, however it will allow you to connect the DSLR to its USB port, and directly transfer your image files (no matter how large the card is).
Is this enough for me to buy an iPad? No, not yet...but it's getting close.