so hey, i hope you come back and check this thread, because I think I can help you.
I was in the same boat a few months ago. I have been using clie's (and a couple of actual palms) as my primary ebook readers since the late 90s, and would probably have gone on doing so forever if the things were still made.
however when my third SJ33 died a couple of years ago, I decided to see if I could jump to something more modern but still possessing the features I need (can upload my own books, backlit screen, fairly high resolution, and preferably an auto-scrolling ebook app.... ooooohhh, deepreader, how i miss you).
so anyway, I "borrowed" my girlfriend's ipod touch and started dicking around with it. I concluded that the screen was good enough pretty quickly, and the battery life seemed to be at least on par with my clie's, so that was fine. what took me forever to find though was a good ebook app. but rather than detailing my months-long search and all the candidates that i tried and rejected, i'll just cut to the punchline:
get eReader. its seems to be based on the same code as the palm app, which was my second favorite ebook reader after deepreader. and it has the two absolute most important features: auto-scrolling, and the ability to add your own books.
seriously. get it. it's free, and you can import your own books. there is one caveat of course: the books have to be in
anyway, i was watching the ipad coverage waiting for the same sort of news. specifically, i wanted to see if the ibooks app would have autoscrolling or at least the ability to add your own books. i didn't see anything about that, but i can at least deduce that the ereader app from my ipod touch should work on an ipad. now granted, it may not look that great upscaled, but i'm hoping that they release a new version that can handle the ipad resolution natively. if so, i'm totally buying that sucker.
so yea, just wanted to drop a line and help out a fellow (non-kindle) ebook reader. good luck, and i hope this works for you!