I just found this thread as I am looking to purchase an eReader. With the iPad now out it added to the quantry. I believe I have decided to not get an iPad because of it's size and weight. I do not want all the bells and whistles it will offer since I have a perfect Sony Vaio with a 13" screen that bows the iPod out of the water for true computer ability and what I need it for. No, I want an eReader for my tech books and personal reading and perhaps magazines and newspapers, and I wat it small, light, portable. I do not own an iPhone so I cannot comment on that idea, and I do not expect to be buying one any time soon. Not that I dislike them, but I am located in Montana where we have limited choices of providers and none offer it. Since most of my tech books are O'Reilly ones, I decided to check the O'Reilly site to see if they could help on the decision, and YES.
Check out http://oreilly.com/ebooks and they list all the formats and readers they work with!
•iPhone, iTouch — Grab the EPUB or PDF and read in the Stanza App, Bookworm, or the reader of your choice.
•iPad — Download the EPUB format and read it on your iPad.
•Android — Read the .apk or .EPUB on your favorite reader.
•Kindle — Get the Mobipocket file and load it onto your Kindle.
•Sony Reader — EPUBs work well on your Sony Reader.
•Computer — Get either the EPUB or PDF.
•Other Mobile Devices — Explore the EPUB with the mobile version of Bookworm.
Because the Kindle is not a standard open format, I am leaning to the Soney Daily Edition, though I wish it were a bit larger like the Kindle DX. Since I will make up my mind and buy my eReader by the end of June, my hope is that Sony with either announce a new one that is a bit larger that I can wait for, or Amazon will get off it's stinking high horse and update the Kindle to handle PDFs better and EPUB format. Either of those will spark my purchase rapidly.